    Gulf War Illnesses: DOD's Conclusions about U.S. Troops' Exposure
    Cannot Be Adequately Supported (01-JUN-04, GAO-04-159).

    Since the end of the Gulf War in 1991, many of the approximately
    700,000 U.S. veterans have experienced undiagnosed illnesses.
    They attribute these illnesses to exposure to chemical warfare
    (CW) agents in plumes--clouds released from bombing of Iraqi
    sites. But in 2000, the Department of Defense (DOD) estimated
    that of the 700,000 veterans, 101,752 troops were potentially
    exposed. GAO was asked to evaluate the validity of DOD,
    Department of Veterans Affairs (VA), and British Ministry of
    Defense (MOD) conclusions about troops' exposure.
    -------------------------Indexing Terms-------------------------
    REPORTNUM:   GAO-04-159
        ACCNO:   A10329
      TITLE:     Gulf War Illnesses: DOD's Conclusions about U.S. Troops'
    Exposure Cannot Be Adequately Supported
         DATE:   06/01/2004
      SUBJECT:   Chemical and biological agents
    	     Data collection
    	     Data integrity
    	     Diseases
    	     Health hazards
    	     Health research programs
    	     Health statistics
    	     Health surveys
    	     Infectious diseases
    	     Statistical data
    	     Veterans
    	     Gulf War Syndrome
    	     Persian Gulf War
    	     Iraq

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    GAO-04-159

    United States General Accounting Office

    GAO

                           Report to Congressional Requesters

    June 2004

                                        GULF WAR
                                       ILLNESSES

      DOD's Conclusions about U.S. Troops' Exposure Cannot Be Adequately Supported

    GAO-04-159

    June 2004

    GULF WAR ILLNESSES

    DOD's Conclusions about U.S. Troops' Exposure Cannot Be Adequately Supported

    DOD's and MOD's conclusions about troops' exposure to CW agents, based on
    DOD and CIA plume modeling, cannot be adequately supported. The models
    were not fully developed for analyzing long-range dispersion of CW agents
    as an environmental hazard. The modeling assumptions as to source term
    data-quantity and purity of the agent-were inaccurate because they were
    uncertain, incomplete, and nonvalidated.

    The plume heights used in the modeling were underestimated, and so were
    the hazard areas. Postwar field testing used to estimate the source term
    did not realistically simulate the actual conditions of bombings or
    demolitions. Finally, the results of all models-DOD and non-DOD
    models-showed wide divergences as to plume size and path.

    DOD's and VA's conclusions about no association between exposure to CW
    agents and rates of hospitalization and mortality, based on two
    epidemiological studies conducted and funded by DOD and VA, also cannot be
    adequately supported because of study weaknesses. In both studies, flawed
    criteria-DOD's plume model and DOD's estimation of potentially exposed
    troops based on this model-were used to determine exposure. This may have
    resulted in large-scale misclassification.

    Troops under the path of the plume were classified as exposed; those not
    under the path, as not exposed. But troops classified as not exposed under
    one DOD model could be classified as exposed under another DOD model.
    Under non-DOD models, however, a larger number of troops could be
    classified as exposed. Finally, as an outcome measure, hospitalization
    rate failed to capture the types of chronic illnesses that Gulf War
    veterans report but that typically do not lead to hospitalization

    Highlights of GAO-04-159, a report to Congressional Requesters

    Since the end of the Gulf War in 1991, many of the approximately 700,000
    U.S. veterans have experienced undiagnosed illnesses. They attribute these
    illnesses to exposure to chemical warfare (CW) agents in plumes-clouds
    released from bombing of Iraqi sites. But in 2000, the Department of
    Defense (DOD) estimated that of the 700,000 veterans, 101,752 troops were
    potentially exposed. GAO was asked to evaluate the validity of DOD,
    Department of Veterans Affairs (VA), and British Ministry of Defense (MOD)
    conclusions about troops' exposure.

    GAO recommends that the Secretary of Defense and the Secretary of Veterans
    Affairs not use the plume-modeling data for any other epidemiological
    studies of the 1991 Gulf War, since VA and DOD cannot know from the flawed
    plume modeling who was and who was not exposed. VA concurred with GAO's
    recommendation, but DOD did not concur.

    GAO also recommends that the Secretary of Defense require no additional
    plume modeling of Khamisiyah and other sites. DOD concurred with GAO's
    recommendation.

    The Central Intelligence (CIA) did not concur with the report, stating
    that it could not complete its review of the draft report in the time
    allotted.

                               The Plume-Modeling Process

                                      Source: GAO.

    Plume hazard area

    www.gao.gov/cgi-bin/getrpt?GAO-04-159.

    To view the full product, including the scope and methodology, click on
    the link above. For more information, contact Keith Rhodes at (202)
    512-6412 or rhodesk@gao.gov.

    Contents

      Letter 1

    Scope and Methodology 3
    Results in Brief 4
    Background 7
    Modeling the Environmental and Health Effects of Fallout from

    CW Agents 10
    DOD's Conclusion about U.S. Troops' Exposure to CW Agents

    Cannot Be Adequately Supported 12
    Major Unresolved Issues Concerning Modeling 19
    DOD's Modeling Efforts Were Flawed 30
    The MOD Relied on U.S. Plume Modeling to Determine Its Troops'

    Exposure 47
    to CW Agents 47
    Total U.S. Plume-Modeling Costs 47
    DOD's and VA's Epidemiological Conclusions on CW Exposure and

    Hospitalization and Mortality Rates Cannot Be Adequately

    Supported 49
    Conclusions 61
    Recommendations for Executive Action 62
    Agency Comments and Our Evaluation 62

    Appendix I DOD's Chronology of Khamisiyah Modeling Events

    Appendix II Power-Law Formula

    Appendix III DOD's Model Divergences

    Appendix IV Divergence and Wind Field Models 69

    Appendix V Comments from the Department of Veterans Affairs 73

      Appendix VI	Comments from the Department of Defense 74
      GAO Comments 92

             Appendix VII Comments from the Central Intelligence Agency 109

    Tables

    Table 1: The Meteorological and Dispersion Models DOD Used to

    Model Khamisiyah Table 2: Gulf War Suspected Chemical Weapon Sites Table
    3: Detector and Agent Identification Systems Deployed by

    Coalition Forces Reporting the Detection of CW Agents Table 4: Principal
    Reported Detections of Chemical Agents in Saudi Arabia, January 17-23,
    1991 Table 5: U.S. Direct Costs for Modeling Gulf War Illnesses

                                         12 22

                                           24

                                         26 48

    Figures

    Figure 1: Timeline of Events Following the U.S. Demolition of CW

    Agents at Khamisiyah, 1991-2000 9 Figure 2: The Plume-Modeling Process 11
    Figure 3: NOAA-11 Meteorological Imagery of Areas Occupied by

    Coalition Forces, January 18-24, 1991 25 Figure 4: Meteorological
    Satellite Photography, Iraq, January 19,

    1991 28 Figure 5: Plume Height Trend Line by Weight of Explosive 31 Figure
    6: Boundary Layer Characteristics 32 Figure 7: Three Types of Plume
    Geometry 33 Figure 8: The Impact of Nocturnal Jets on a Plume at Higher

    Altitudes 34 Figure 9: Lawrence Livermore National Laboratory Projection
    39 Figure 10: DOD Composite Projection 41 Figure 11: DOD Composite
    Projection and Lawrence Livermore

    National Laboratory Projection 43 Figure 12: Validation Runs of Various
    Models 44 Figure 13: Divergence in Models Used to Construct DOD and CIA

    Composite Analyses 67 Figure 14: Divergence in DOD Muhammadiyat Models 68
    Figure 15: Lawrence Livermore National Laboratory Diagnostic

    Wind Model, Based on Observational Data 70 Figure 16: Lawrence Livermore
    National Laboratory Diagnostic Wind Model, Based on ECMWF Projections 71
    Figure 17: Wind Field Vector Model, Based on COAMPS 72

    Abbreviations

    ADPIC Atmospheric Dispersion by Particle-in-Cell
    AFTAC Air Force Technical Applications Center
    BSS body-system symptom
    CAPS Clinician Administered Posttraumatic Stress
    CDC Centers for Disease Control and Prevention
    CES Combat Exposure Scale
    CIA Central Intelligence Agency
    COAMPS Coupled Ocean-Atmosphere-Mesoscale Prediction System
    CW chemical warfare
    DIA Defense Intelligence Agency
    DMDC Defense Manpower Data Center
    DOD Department of Defense
    DOE Department of Energy
    DTRA Defense Threat Reduction Agency
    GDAS Global Data Assimilation System
    HPAC Hazard Prediction and Assessment Capability
    IDA Institute for Defense Analyses
    LLNL Lawrence Livermore National Laboratory
    MM5 Mesoscale Model Version 5
    MOD Ministry of Defense
    NOAA National Oceanic and Atmospheric Administration
    NOGAPS Naval Operational Global Atmospheric Prediction System
    NUSSE Non-Uniform Simple Surface Evaporation
    OMEGA Operational Multiscale Environmental Model with Grid

    Adaptivity PON paraoxonase/arylesterase enzyme PTSD Post-Traumatic Stress
    Disorder RAMS Regional Atmospheric Modeling System SAIC Science
    Applications International Corporation SCIPUFF Second-order Closure
    Integrated Puff UNMOVIC United Nations Monitoring, Verification, and
    Inspection

    Commission UNSCOM United Nations Special Commission VA Department of
    Veterans Affairs VLSTRACK Vapor, Liquid, and Solid Tracking WMO World
    Meteorological Organization

    This is a work of the U.S. government and is not subject to copyright
    protection in the United States. It may be reproduced and distributed in
    its entirety without further permission from GAO. However, because this
    work may contain copyrighted images or other material, permission from the
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    separately.

    United States General Accounting Office Washington, DC 20548

    June 1, 2004

    The Honorable Robert C. Byrd Ranking Minority Member Committee on
    Appropriations United States Senate

    The Honorable Christopher Shays

    Chairman

    Subcommittee on National Security, Emerging Threats, and International
    Relations Committee on Government Reform House of Representatives

    Many of the approximately 700,000 U.S. veterans of the Gulf War have
    experienced undiagnosed illnesses since the war's end in 1991. Some
    veterans fear they are suffering from chronic disabling conditions because
    of exposure to chemical warfare (CW) agents, as well as vaccines,
    pesticides, and other hazardous substances with known or suspected adverse
    health effects. They believe that their exposure may have been caused by
    the Coalition forces' bombing of several sites in Iraq, including storage
    and production facilities for nuclear, biological, or chemical warfare
    agents. DOD's estimates based on available bomb damage assessment during
    the war are that 16 of the 21 sites that were bombed were destroyed. Many
    U.S. and British troops were located near some of these sites. In
    addition, in March 1991, after the end of the war, U.S. troops conducted
    large-scale demolition operations to destroy munitions and facilities at
    Khamisiyah, a forward-deployed site in Iraq. These munitions were later
    found to have been filled with CW agents.

    When the possible exposure of U.S. troops to low levels of CW agents first
    became an issue, during summer 1993, the Department of Defense (DOD) and
    the Central Intelligence Agency (CIA) concluded that no troops had been
    exposed because (1) there were no forward-deployed CW agent munitions and
    (2) plumes-clouds of CW agents released from the bombing that destroyed
    the chemical facilities-could not have reached the troops.

    This conclusion was maintained until June 1996, when DOD publicly
    acknowledged that U.S. troops had destroyed stockpiles of chemical
    munitions at Khamisiyah after the war. Khamisiyah was a large

    ammunition storage depot that contained nearly 100 ammunition storage
    bunkers covering 25 sq km. Earlier, in October 1991, United Nations
    Special Commission (UNSCOM) inspectors had found evidence of munitions
    containing CW agents at Khamisiyah. Specifically, among the nearly 100
    bunkers at Khamisiyah, remnants of 122 mm rockets were identified at
    Bunker 73. The rockets were found to have been filled with a combination
    of sarin and cyclosarin nerve agents. Several hundred 122 mm rockets
    containing the same nerve agents were also found at a pit area close to
    Bunker 73. It was not until 1996 that UNSCOM conclusively determined that
    CW agents were in Bunker 73.

    Since DOD's 1996 recognition that the bombing and demolition of Iraqi
    facilities during the war did result in the release of plumes, DOD has
    conducted numerous investigations, studies, and analyses based on computer
    modeling. DOD has sought to determine the potential hazard area-the path
    of the plume-and the U.S. troops who may have been exposed to
    contamination from the bombing and demolition of storage facilities
    containing CW agents (see appendix. I).1 In June 1996, DOD estimated that
    300 to 400 U.S. troops participated in the demolition of Khamisiyah Bunker
    73. In August 1996, the CIA, from the results of its computer modeling,
    stated that around Khamisiyah, an area as large as 25 km downwind and 8 km
    wide could have been contaminated.2

    In September 1996, DOD estimated that 5,000 troops had been within a 25 km
    radius of Khamisiyah. In October 1996, DOD extended this radius to 50 km:
    It estimated that 20,000 U.S. troops had been within this zone. In July
    1997, from the first plume analyses, DOD estimated that 98,910 U.S. troops
    had potentially been exposed. In 2000, additional analyses led DOD to
    reestimate that 101,752 U.S. troops had potentially been exposed.

    In response to your request, we evaluated how well conclusions-about the
    extent of exposure of U.S. troops and the association between CW exposure
    and troops' hospitalization and mortality rates-are supported by available
    evidence. We presented our preliminary results to you in our

    1Appendix I contains a detailed chronology of DOD's modeling events.

    2Central Intelligence Agency, CIA Report on Intelligence Related to Gulf
    War Illnesses (McLean, Va.: Aug. 2, 1996).

    Scope and Methodology

    testimony in June 2003.3 In this report, we present our final results.
    Specifically, we have assessed the following:

    1. 	How valid is the DOD and British Ministry of Defense (MOD)
    conclusion-based on CIA and DOD plume-modeling results-about U.S. and
    British troops' exposure to CW agents?

    2. 	What were the total costs for the CIA's and DOD's various
    plumemodeling efforts?

    3. 	How valid are the DOD and Department of Veterans Affairs (VA)
    conclusions from epidemiological studies, based on DOD's plumemodeling
    results, that there was no association between CW exposure at Khamisiyah
    and the troops' hospitalization and mortality rates?

    To determine the validity of DOD's conclusion, based on its plumemodeling
    analysis, that U.S. troops' exposure to CW agents was as low as it said it
    was, we examined the meteorological and dispersion models DOD used to
    model chemical agent releases from the U.S. demolition of Khamisiyah and
    Coalition bombings of Al Muthanna and Muhammadiyat in Iraq during the Gulf
    War. We evaluated the basis for technical and operational assumptions DOD
    made in the models and the specific data and information on source term,
    meteorological conditions, and other key parameters used for modeling
    chemical releases from Iraqi sites. We also evaluated the efforts of the
    CIA and DOD to collect and develop data on source term and other key
    parameters for the modeling.

    We interviewed DOD and CIA modelers and officials involved with the
    modeling and obtained documents and reports from DOD's Deployment Health
    Support Directorate. We also interviewed and received documents from
    Department of Energy (DOE) officials who were involved with the modeling
    at DOE's Lawrence Livermore National Laboratory (LLNL). In addition, we
    interviewed officials and obtained documents from the

    o  	Institute for Defense Analyses (IDA) concerning the IDA expert panel
    assessment of CIA's modeling of Khamisiyah,

    3U.S. General Accounting Office, Gulf War Illnesses: Preliminary
    Assessment of DOD Plume Modeling for U.S. Troops' Exposure to Chemical
    Agents, GAO-03-833T (Washington, D.C.: June 2, 2003). www.gao.gov.

    o  	U.S. Army Dugway Proving Ground in Utah to determine how CW agents in
    Iraq's rockets might have been released during the Khamisiyah pit area
    demolitions,

    o  	U.S. Army Center for Health Promotion and Preventive Medicine to
    determine how specific troop unit exposures were identified, and

    o  	United Nations Monitoring, Verification, and Inspection Commission
    (UNMOVIC) to obtain information on source term from UNSCOM's analyses and
    investigations on Khamisiyah, Al Muthanna, and Muhammidiyat.

    To determine the validity of DOD's and VA's conclusions-based on
    epidemiological studies-that there was no association between Khamisiyah
    exposure and the rates of hospitalization or mortality, we reviewed
    published epidemiological studies in which hospitalization and mortality
    among exposed and nonexposed U.S. troops were analyzed. We also
    interviewed the study authors and researchers involved with the studies
    and examined the Gulf War Khamisiyah population databases DOD provided in
    support of these studies. We interviewed Veterans Benefits Administration
    officials and obtained documents and reports on their analysis of DOD's
    population databases. We did not examine whether plume modeling data were
    being used by VA to determine eligibility for treatment or compensation.

    To identify total costs associated with modeling and analysis of CW agent
    releases during the Gulf War, we interviewed officials and collected cost
    data from various DOD agencies and contractors who supported the modeling
    efforts. However, total costs incurred could not be determined because DOD
    agencies and other organizations could provide only direct costs, not
    their indirect costs, associated with the modeling.

    To determine the extent of British troops' exposure to CW agent releases
    during the Gulf War, we interviewed MOD officials in London and Porton
    Down, and we reviewed MOD reports concerning the effect of exposure to CW
    agent releases on British forces.

    We conducted our work from May 2002 through May 2004 in accordance with
    generally accepted government auditing standards.

    Results in Brief	DOD's and MOD's conclusions, based on DOD's plume
    modeling, about their troops' exposure to CW agents cannot be adequately
    supported.

    Given the inherent weaknesses associated with the specific models they
    used and the lack of accurate and appropriate meteorological and source
    term data in their analyses, we found five major reasons to question their
    conclusions. First, the models were not fully developed for analyzing
    longrange dispersion of CW agents as an environmental hazard. Second,
    assumptions regarding source term data used in the modeling-such as the
    quantity and purity of the agent-were inaccurate, since they were based on
    (1) uncertain and incomplete information and (2) data that were not
    validated. Third, the plume heights from the Gulf War bombings were
    underestimated in DOD's models. Fourth, postwar field testing at the U.S.
    Army Dugway Proving Ground to estimate the source term data did not
    reliably simulate the actual conditions of either the bombings or the
    demolition at Khamisiyah. Fifth, there is a wide divergence in results
    among the individual models DOD selected, as well as in the DOD and
    non-DOD models, with regard to the size and path of the plume and the
    extent to which troops were exposed. Therefore, given these inherent
    weaknesses, DOD and MOD cannot know which troops were and which troops
    were not exposed.

    The total costs for the various plume-modeling efforts to analyze the
    potential exposure of U.S. troops-from the demolition at Khamisiyah and
    the bombing of several sites in Iraq-cannot be estimated. DOD
    organizations and other entities involved with the plume-modeling efforts
    could provide only their direct costs (that is, contractors' costs), which
    totaled about $13.7 million. However, this amount does not include an
    estimate of the considerable indirect costs associated with the salaries
    of DOD, VA, and contractors' staff or costs of facilities, travel, and
    equipment. We requested, but DOD could not provide, this estimate. In
    addition, the CIA would not provide direct and indirect costs for Gulf War
    plume modeling because, in its view, our request constituted oversight of
    an intelligence matter and is beyond our scope of authority. The CIA's
    contractor, the Science Applications International Corporation (SAIC),
    also did not respond to our request.

    DOD's and VA's conclusions-that there was no association between exposure
    to CW agents at Khamisiyah and U.S. troops' rates of hospitalization and
    mortality-also cannot be adequately supported. DOD and VA based their
    conclusions on two epidemiological studies they

    funded, one conducted by DOD researchers, the other by VA researchers.4 In
    both of these studies, flawed criteria were used to determine the troops'
    exposure. For example, the studies' criteria were based on (1) the DOD
    plume model of exposure from postwar demolition of the Khamisiyah
    munitions depot and (2) DOD's estimation, using this modeling, of which
    troops might have been under the path of the plume. Troops under the path
    of the plume were classified as exposed, those not under the path as
    nonexposed. However, troops classified as nonexposed under one DOD model
    could be classified as exposed under another DOD model, thereby
    confounding the results. In the DOD models, a small area was identified as
    being under the path of the plume, resulting in a small number of troops
    identified as exposed. But in a model DOD used from LLNL, for example, a
    much larger area was identified under the path of the plume, resulting in
    a large number of troops exposed; in addition, these exposed troops
    included different troops from those in the DOD models.

    These flaws may have resulted in large-scale misclassification of the
    exposure groups-that is, a number of exposed veterans may have been
    classified as nonexposed, and a number of nonexposed veterans may have
    been misclassified as exposed. In addition, in the hospitalization study,
    the outcome measure-number of hospitalizations-failed to capture the
    chronic illnesses of Gulf War veterans, which are commonly reported but
    typically do not lead to hospitalization. Some published scientific
    studies of exposure involving Gulf War veterans, studies of genetic
    anomalies, and animal exposure-response studies suggest an association
    between lowlevel exposure to CW agents and chronic illnesses.

    We recommend that the Secretary of Defense and the Secretary of Veterans
    Affairs not use the plume-modeling data for future epidemiological studies
    of the 1991 Gulf War, since VA and DOD cannot know from the flawed plume
    modeling who was and who was not exposed.

    We recommend that the Secretary of Defense require no further plume
    modeling of Khamisiyah and the other sites bombed during the 1991 Gulf War
    in order to determine troops' exposure. Given the uncertainties in the

    4G. C. Gray and others, "The Postwar Hospitalization Experience of Gulf
    War Veterans Possibly Exposed to Chemical Munitions Destruction at
    Khamisiyah, Iraq," American Journal of Epidemiology 150 (1999); H. K. Kang
    and T.A. Bullman, "Mortality among U.S. Veterans of the Persian Gulf War:
    7 Year Follow-Up, "American Journal of Epidemiology 154 (2001): 399-409.

    Background

    source term and meteorological data, additional modeling of the various
    sites bombed would likely result in additional costs while still not
    providing DOD with any definitive data on who was or was not exposed.

    We obtained comments on a draft of this report from VA, DOD, and CIA. VA
    concurred with our first recommendation (see appendix V). DOD did not
    concur with our first recommendation, indicating that it apparently
    represents a blanket prohibition of plume modeling in the future. The
    intent of our recommendation is only directed at epidemiological studies
    involving the DOD and CIA plume modeling data from the 1991 Gulf War and
    not a blanket prohibition of plume modeling in the future (see appendix
    VI). We have clarified the recommendation along these lines. DOD concurred
    with our second recommendation, indicating that despite enhancements in
    the modes, uncertainties will remain (see appendix VI). CIA did not concur
    with the report, indicating that it could not complete their review in the
    time allotted (see appendix VII).

    In March 1991, after the Gulf War had ended, U.S. Army demolition units
    destroyed munitions in Bunker 73 and in an open pit at the Khamisiyah
    ammunition storage depot in southeastern Iraq. In October 1991, it was
    discovered, from inspections conducted by UNSCOM that hundreds of 122 mm
    rockets destroyed at Khamisiyah had contained nerve agents sarin and
    cyclosarin.

    U.S. and Coalition forces also bombed many other known or suspected Iraqi
    CW research, materiel, storage, and production sites. According to the CIA
    and DOD, Coalition aerial bombings resulted in damage to filled chemical
    munitions at only two facilities in central Iraq-Al Muthanna Bunker 2 and
    Muhammadiyat-and at one facility in southern Iraq-the Ukhaydir ammunition
    storage depot. During these aerial bombings, munitions were damaged at Al
    Muthanna containing an estimated 17 metric tons of sarin and cyclosarin
    and at Muhammadiyat containing an estimated 2.9 metric tons of sarin and
    cyclosarin and 15 metric tons of the chemical agent mustard.

    According to DOD, the connection between the CW agent munitions UNSCOM
    found at Khamisiyah and U.S. demolition operations there had not been
    immediately made. However, in 1996, concerns that the Presidential
    Advisory Committee on Gulf War Illnesses raised prompted

    the CIA to examine this issue.5 In early 1996, after linking Khamisiyah to
    the presence of CW agents, based on UNSCOM and other reporting, the CIA
    contracted with SAIC to conduct an initial analysis and modeling of the
    bombing of chemical munitions in Khamisiyah Bunker 73.

    The CIA issued two reports. The first report, in August 1996, modeled a
    potential release of agents from Khamisiyah Bunker 73 and from Al Muthanna
    and Muhammadiyat.6 However, when modeling of the pit area at Khamisiyah
    began, the CIA realized that the source term data-such as the quantity and
    the purity of the agent and data on meteorological conditions, including
    the wind and the weather patterns-were not available. Because of these
    uncertainties, DOD and the CIA asked IDA to convene an independent panel
    of experts to review the modeling. The IDA expert panel conducted its
    review from November 1996 to February 1997 and (1) reported that the
    initial analyses of the pit area were inadequate and (2) recommended
    taking different approaches to improve the modeling.

    The CIA issued its second report jointly with DOD in September 1997, this
    time focusing on an open pit area at Khamisiyah.7 This report combined the
    results of five different meteorological and dispersion models that the
    CIA and DOD used to project the size and path of the plume from the
    demolition operations. In 2000, DOD remodeled the Khamisiyah pit site,
    using updated CIA source assessments and troop location data, which
    changed the projected hazard area. The 1991-2000 timeline of major events
    at Khamisiyah is shown in figure 1.

    5The Presidential Advisory Committee on Gulf War Veterans' Illnesses was
    established by Executive Order 12961 on May 26, 1995, to provide oversight
    for Gulf War illness investigations; it terminated in November 1997.
    http://www.gwvi.ncr.gov/ (Apr. 26, 2004).

    6Central Intelligence Agency, CIA Report on Intelligence.

    7Central Intelligence Agency and the Department of Defense, Modeling the
    Chemical Warfare Agent Release at the Khamisiyah Pit (McLean, Va.: Sept.
    1997).

    Figure 1: Timeline of Events Following the U.S. Demolition of CW Agents at
                                 Khamisiyah, 1991-2000

                                      Source: GAO.

    Modeling the Environmental and Health Effects of Fallout from CW Agents

    According to the CIA, modeling is the art and science of using
    interconnected mathematical equations to predict the activities of an
    actual event. In this case, modeling was used to determine the direction
    and extent of the plume from CW agents. In environmental hazard modeling,
    simulations recreate or predict the size and path (that is, the direction)
    of the plume, including the potential hazard area, and potential exposure
    levels are generated.

    Modeling requires several components of accurate information:

    o  	the characteristics or properties of the material that was released
    and the rate of release (for example, quantity and purity, the vapor
    pressure, the temperature at which the material burns, particle size, and
    persistency and toxicity),

    o  	temporal information (for example, whether chemical agent was
    initially released during daylight hours, when it might rapidly disperse
    into the surface air, or at night, when a different set of breakdown and
    dispersion characteristics would pertain, depending on terrain, plume
    height, and rate of agent degradation),

    o  	data that drive meteorological models during the modeled period (for
    example, temperature, humidity, barometric pressure, dew point, wind
    velocity and direction at varying altitudes, and other related measures of
    weather conditions), and

    o  	data from global weather models to simulate large-scale weather
    patterns and from regional and local weather models to simulate the
    weather in the area of the chemical agent release and throughout the area
    of dispersion.

    In addition, in modeling, information is required on the potentially
    exposed populations, animals, crops, and other assets that may be affected
    by the agent's release.

    The process flow for chemical plume modeling, to estimate the plume hazard
    area, is shown in figure 2.

                          Figure 2: The Plume-Modeling Process

    Plume hazard area

                                 Meteorological Models

    Various plumes during the 1991 Gulf War were modeled with global-scale
    meteorological models, such as the National Centers for Environmental
    Prediction Global Data Assimilation System (GDAS) and the Naval
    Operational Global Atmospheric Prediction System (NOGAPS). Regional and
    local weather models were also used, including the Coupled
    Ocean-Atmosphere Mesoscale Prediction System (COAMPS), the Operational
    Multiscale Environmental Model with Grid Adaptivity (OMEGA), and the
    Mesoscale Model Version 5 (MM5). Outputs from global weather models are
    mainly used as initial and boundary conditions for regional weather
    models.

                                      Source: GAO.

    Transport and Diffusion Models

    Transport and diffusion models were also used during the Gulf War.8 These
    models project both the path of a plume and the degree of potential hazard
    posed by the agents. Dispersion models used during the Gulf War included
    the Hazard Prediction and Assessment Capability (HPAC) model, along with
    the HPAC component, the Second-order Closure Integrated Puff (SCIPUFF)
    model; the Vapor, Liquid, and Solid Tracking (VLSTRACK) model; the
    Non-Uniform Simple Surface Evaporation (NUSSE) model; and the Atmospheric
    Dispersion by Particle-in-Cell (ADPIC) model.

    The meteorological and dispersion models DOD used to model Khamisiyah are
    shown in table 1.

    8We use dispersion in this report to refer to both transport and diffusion
    models.

    Table 1: The Meteorological and Dispersion Models DOD Used to Model
    Khamisiyah

                            Model type Developer or sponsor

    Meteorological

    COAMPS: Coupled Ocean-Atmosphere Mesoscale Prediction System U.S. Navy

    MATHEW: Mass Consistent Wind Fielda	Department of Energy, Lawrence
    Livermore National Laboratory

        MM5: Mesoscale Model Version 5 National Center for Atmospheric Research

    NOGAPS: Naval Operational Global Atmospheric Prediction System, U.S. Navy

    OMEGA: Operational Multiscale Environment Model with Grid Adaptivity
    Defense Threat Reduction Agency

    Dispersion

    ADPIC: Atmospheric Dispersion by Particle-in-Cella	Department of Energy,
    Lawrence Livermore National Laboratory

    HPAC/SCIPUFF: Hazard Prediction and Assessment Capability/Second-Defense
    Threat Reduction Agency order Closure Integrated Puff

    NUSSE4: Non-Uniform Simple Surface Evaporation, Version 4 U.S. Army

    VLSTRACK: Vapor, Liquid, Solid Tracking U.S. Navy

    Source: Department of Defense, Technical Report: Modeling and Risk
    Characterization of U.S. Demolition Operations at the Khamisiyah Pit
    (Washington, D.C.: Apr. 2002).

    DOD's Conclusion about U.S. Troops' Exposure to CW Agents Cannot Be
    Adequately Supported

    aInstitute of Defense Analysis used this model in its analysis of
    Khamisiyah modeling, an analysis done at DOD's request.

    DOD's conclusion about the extent of U.S. troops' exposure to CW agents
    from the Gulf War, based on CIA and DOD plume models, cannot be adequately
    supported because of uncertainty associated with the source term data and
    meteorological data. The models are neither sufficiently certain nor
    sufficiently precise to draw definitive conclusions about the size or path
    (that is, the direction) of the plumes.

    In particular, we found five reasons to question DOD's conclusion. First,
    the models DOD selected were not fully developed for analyzing longrange
    dispersion of CW agents as environmental hazards. Second, the assumptions
    about the source term data used in the models were inaccurate. Third, in
    most of the models, the plume height was significantly underestimated.
    Fourth, postwar field testing at the U.S. Army Dugway Proving Ground in
    Utah to estimate the source term data did not realistically simulate the
    actual conditions of the demolition operations at Khamisiyah or the
    effects of the bombings at any of the other sites in Iraq. And fifth,
    there are wide divergences among the individual models DOD selected with
    regard to the size and path of the plume and the extent to which troops
    were exposed.

    DOD's Models Were Not Fully Developed for Analyzing Long-Range
    Environmental Hazards

    COAMPS and OMEGA Meteorological Models

    VLSTRACK and HPAC Dispersion Models

    CIA and DOD officials selected several in-house models for plume models.
    For Khamisiyah and the other Iraqi sites, DOD selected the COAMPS and
    OMEGA meteorological models and the HPAC/SCIPUFF and VLSTRACK dispersion
    models. However, at the time, these models were not fully developed for
    long-range environmental hazards. In particular, they were inappropriate
    for the long-range tracking of chemical agents.

    Although COAMPS was accepted by the DOD peer review panel, OMEGA was still
    under development. The DOD 1997 peer review panel that was reviewing the
    models chosen for the 1997 Khamisiyah analysis reported problems with
    OMEGA that resulted in major errors in its simulations. In the analyses of
    Khamisiyah, as well as Al Muthanna, according to an IDA technical review
    panel, OMEGA consistently underpredicted surface wind speeds by a factor
    of 2 to 3, compared with actual observations collected at five World
    Meteorological Organization (WMO) stations in the area.

    VLSTRACK had been developed primarily to predict immediate health hazards
    (that is, lethal or incapacitating effects) associated with troops' direct
    exposure to CW agents. It was not developed for predicting longterm health
    effects from indirect exposure to low levels of these agents. According to
    modeling experts at the Naval Surface Warfare Center, the 2-month IDA
    panel reanalysis and modeling was a developmental effort because existing
    models did not have the capability to perform the required predictions.
    Considerations of dispersion areas associated with low-level exposure to
    CW agents released in Iraq, such as nerve and blister agents, required
    these experts to make many extensions and modifications to some of the
    methodology in VLSTRACK.

    HPAC was developed jointly by the Defense Intelligence Agency (DIA) and
    the Defense Special Weapons Agency-now the Defense Threat Reduction Agency
    (DTRA)-and was specifically tailored for counterproliferation contingency
    planning. In a 1998 scientific review and evaluation of the SCIPUFF
    dispersion model (an integral component of HPAC), the National Oceanic and
    Atmospheric Administration's (NOAA) Air Resources Laboratory reported that
    SCIPUFF was better suited for short-range dispersion applications of about
    10 km than for long-range transport modeling. One of HPAC's weaknesses is
    that it does not provide definitive answers because of uncertainties about
    agent transport, plume location, and weather.

    It is also evident, from NOAA's review, that a group using VLSTRACK might
    receive significantly divergent results from a group using HPAC. Further,
    neither model is sufficiently accurate to permit a conclusion that the
    path of the plume is confined to the hazard area that the model predicts.

    In a September 1998 memorandum, the Deputy to the Secretary of Defense for
    Counterproliferation and Chemical and Biological Defense cited a DOD panel
    study team finding that the VLSTRACK and HPAC models generate hazard
    predictions that differ significantly from each other: "This occurred even
    when the source terms and weather inputs are as simple and as identical as
    possible. In operational deployment, the average model user could obtain
    different answers for the same threat."

    A former Modeling and Simulation Adviser to the Deputy for
    Counterproliferation and Chemical and Biological Defense told us that the
    reliability of these models was of extreme concern. Also, in 1998, at IDA,
    a panel study's initial comparison of the hazard-prediction models HPAC
    and VLSTRACK documented substantial differences-by factors between 5 and
    1,000-between the models for the prediction of the same event. The most
    significant errors in the coding and the potential for misuse were found
    in HPAC and its subcomponent models. Given these problems with the
    analyses conducted up to 1998, HPAC could not be considered reliable.

    In 1997, the director of NOAA's Air Resources Laboratory stated that DOD's
    model selection resulted in the use of in-house models that were not well
    known outside DOD. As to the meteorological models, he noted that three
    mainstream mesoscale models were available, such as MM5 and Regional
    Atmospheric Modeling System (RAMS), that were well accepted for deriving
    site-specific flow conditions from large-scale meteorological information.
    DOD used MM5 in both its 1997 and 2000 modeling.

    DOD's Models Included Source Term Assumptions That Cannot Be Verified

    The source term data DOD used in the modeling for sites at Khamisiyah, as
    well as Al Muthanna and Muhammadiyat, contain significant unreliable
    assumptions. DOD and the CIA based assumptions on field testing,
    intelligence information, imagery, UNSCOM inspections, and Iraqi
    declarations to UNSCOM. However, these assumptions were based on limited,
    nonvalidated, and unconfirmed data concerning (1) the nature of the
    Khamisiyah pit demolition, (2) meteorology, (3) agent purity, (4) amount
    of agent released, and (5) other CW agent data. In addition, DOD and the
    CIA excluded, for modeling, many other sites and potential hazards
    associated with the destruction of binary chemical weapons, CW

    agent precursor materials, and the potential release of CW agents and
    toxic byproducts from other sites.9

    During the initial modeling of the demolition of CW agent munitions at the
    Khamisiyah pit, the CIA did not have the data-the number of rockets
    present, agent purity, amount of agent released into the atmosphere, agent
    reaction in an open-pit demolition, and prevailing meteorological
    conditions-on how rockets with chemical warheads would be affected by
    open-pit demolition compared with bunker demolition. A 1996-97 IDA panel
    found substantial uncertainty about the number of damaged rockets that
    might have released CW agents and how rapidly they were released. The
    panel also found that the CIA and SAIC had used what were, "essentially,
    guesses" to make up for the lack of data on how much agent was released
    and over what period of time. For example, the CIA based the number of
    rockets on the number known to have been there before the demolition and
    the number UNSCOM found during inspections. But, according to the IDA
    panel, the difference between what was estimated and what UNSCOM found
    varied by a factor of 5 or 6.

    Meteorological data at Khamisiyah were lacking because relatively few
    observations had been made, according to DOD modelers, and those that had
    been made were far from the site. This lack of meteorological observation
    applied also to the modeling of other sites. Observations were few because
    Iraq stopped reporting weather station measurement information to WMO in
    1981. As a result, data on the meteorological conditions in Iraq during
    the Gulf War were not available.

    At Khamisiyah, the only data available were for the surface wind
    observation site, 80 to 90 km away, and for the upper atmosphere, about
    200 km away. At other sites modeled, the nearest data were at even greater
    distances. The IDA panel recognized that wind patterns could contain areas
    of bifurcation-lines where winds move in one direction on one side and in
    another direction on another side-which migrate over time and are
    different at varying altitudes.

    Assumptions about the purity of the CW agents sarin and cyclosarin
    established for Khamisiyah, Al Muthanna, Muhammadiyat, and Ukhaydir
    differed widely. In each case, agent purity was a key factor in the CIA
    and

    9A binary weapon mixes two less toxic materials to create a toxic nerve
    agent within the weapon when it is fired or dropped.

    DOD methodology for determining the amount of agent released. For example,
    for modeling purposes, 10 tons of agents with a purity of 18 percent would
    be represented as 1.8 tons of agent. The CIA relied on UNSCOM reporting on
    the amount of CW agents Iraq produced. But to establish these rates,
    UNSCOM relied primarily on Iraqi declarations and Iraqi production
    records, other UNSCOM testing, and assumptions about the extent of agent
    degradation.

    For example, according to Iraqi production records UNSCOM obtained, the
    agent purity at Khamisiyah in early January 1991 was about 55 percent. The
    agent degraded to 10 percent purity by October 1991, when laboratory
    analysis had been completed on samples taken by UNSCOM from one of the
    rockets. On the basis of the initial sample purity and the projected
    degradation rate for sarin and cyclosarin, the CIA assessed that the ratio
    of sarin to cyclosarin when the munitions were blown up, in March 1991,
    was the same as that sampled in October 1991-3:1. According to the CIA,
    "assuming a conservative exponential degradation" of the sarin and
    cyclosarin, the purity on the date of demolition, 2 months after
    production, was calculated at about 50 percent.

    At Al Muthanna, where sarin was stored in a bunker, the CIA estimated that
    it had deteriorated to approximately 18 percent purity by early February
    1991, when Bunker 2 was destroyed, leaving the equivalent of about 1,600
    kg (1.6 metric tons) of viable sarin. Iraqi records recovered by UNSCOM
    inspectors suggested that the agent in Bunker 2 was from 1988 production
    runs. UNMOVIC confirmed that in UNSCOM testing of other sarin samples,
    produced during 1998, the maximum purity of agent had degraded to a range
    of 18 percent to 2 percent by 1991.

    According to a 2002 CIA assessment, only 2.5 percent of sarin was released
    from the demolition of rockets in Bunker 73 at Khamisiyah.10 This
    assessment was based on comparisons with U.S. testing in the 1960s at
    Black Hills, South Dakota, on sarin-filled rockets.11 The CIA considered
    the 2.5 percent estimate conservative because agent-heating conditions
    were

    10Central Intelligence Agency, Intelligence Update: Chemical Warfare Agent
    Issues during the Persian Gulf War (McLean, Va.: Apr. 2002).

    11U.S. Army Dugway Proving Ground, Hazard Classification Tests of Igloo
    Storage of GBand VX-Filled M55 Rockets, RTD&E Project 1B650312D624,
    USATECOM Project 5-3-013502, DPGDR C-505 (Dugway, Utah: Apr. 1966).

    harsher in Bunker 73 than in the Black Hills tests. The 2002 CIA
    assessment included this statement:

    Far less agent (a maximum of 0.01 percent) would have been released in the
    Al Muthanna bunker incident than the 2.5 percent indicated by 1960s US
    field tests at Black Hills, South Dakota. The Black Hills tests used
    simulated bunkers that had a wood slat, sand ceiling, and earth walls.
    Those bunkers did not allow heat to build up as rapidly as in an Iraqi
    bunker with thick reinforced concrete ceiling and walls. However, we have
    chosen 10 kilograms as the release amount to account for unmodeled
    releases from rocket flyouts or

    12

    transients at the beginning of the fire.

    The CIA assessed that far less agent would have been released in the Al
    Muthanna bunker because, based on U.S. field testing with simulated
    bunkers, heat would build up rapidly in Iraqi bunkers made of thick
    reinforced concrete ceiling and walls, destroying most of the agent.

    DOD's Postwar Field Testing Did Not Realistically Simulate Actual
    Conditions of Demolition Operations

    During the 1960s Black Hills testing, rockets filled with sarin and VX
    nerve agents were intentionally ignited by thermite grenades-alone and
    with the addition of diesel fuel-as well as by fused initiation of the
    burster explosive charge. According to the testing report, on the first
    trial, the 11 crates of rockets were stacked 18 in. from the front wall on
    the right side of the igloo. Because of safety considerations, a centrally
    located burster was ignited with a 10-min. safety time fuse instead of an
    electric blasting cap. Once detonated, there were 104 major explosions
    during the 3 hrs. and 4 min. of observation. The maximum pressure recorded
    during the initial detonation was 19 lbs./sq. in. above atmospheric
    pressure. The maximum pressure during the trial was 621-oC, which was
    recorded 15 min. after the ignition of the burster. The igloo sustained
    three wide cracks in the arch and two large holes on either side of the
    door. The only major debris found outside the igloo was the partial body
    of one M55 rocket, located approximately 200 ft. away. Because of the
    damage to the igloo, the test was deemed an official disaster.

    During a second trial, crated rockets, with bursters removed, were stacked
    as in the first trial. Two thermite grenades were set on top of the crates
    at the motor end and were ignited with a 10-min. safety time fuse. The
    grenades functioned properly but failed to ignite the rocket motors or
    crate material. One day later, 12 thermite grenades were placed in three

    12Central Intelligence Agency, Intelligence Update, p. 62.

    groups of four, at the motor end of the crates, and 5 gal. of diesel fuel
    were poured over the 11 crates just before ignition with a safety fuse.
    From 2 crates, 12 rocket motors were ignited and hit the rear wall of the
    igloo, but the only damage found was a slight bulge in the bottom of the
    igloo door. The igloo withstood the fire and contained the rockets.

    According to a later DOD study, based on the analysis in the 1960s of
    Dugway Proving Ground Trial C505, from a fire within an igloo containing
    GB-filled M55 rockets, the estimated amount of agent released was assumed
    to be 2.52 percent over a 60-min. interval.13 This appears to be the basis
    for the conclusion that only approximately 2.5 percent of the agent would
    have been released.

    However, the bunkers at Al Muthanna and other locations in Iraq were not
    deliberately set on fire with incendiary devices. They were targeted with
    high-explosive weapons such as Tomahawk missiles and laser-guided and
    nonguided bombs, which detonate and produce instantaneous and extreme
    blast forces, as well as shock and pressure waves and heat. A high
    explosive is one in which the speed of reaction (typically 5,000 to 8,000
    m/s) is faster than the speed of sound in the explosive. High explosives
    produce a shock wave along with gas, and the characteristic duration of a
    high-explosive detonation is measured in microseconds (10-6 s). Further,
    if an explosion is confined within a chamber or room, the gas pressure
    increases rapidly to a sustained level and then decays by venting out.
    Under these conditions, shock reflections occur and the overall effect can
    be greater than that of the incident shock.14 While the CIA analysts gave
    much credibility to blast heat, no consideration was given to either the
    shock blast effects of the munitions or the higher altitude plumes
    generated from the transfer of mass associated with the shock waves.
    Further, the CIA stated that its conclusion was supported by UNSCOM's
    physical inspections of Bunker 2. UNMOVIC, however, informed us that
    UNSCOM had not physically inspected this bunker for safety reasons
    relating to structural instability.

    13U.S. Army Armament, Munitions, and Chemical Command, Chemical Research
    Development and Engineering Center, Source Characteristics of a Fire
    within an Igloo Filled with M55 Chemical Munitions, CRDEC-TR-87056 (Rock
    Island, Ill.: May 1987).

    14National Academy of Sciences, Commission on Engineering and Technical
    Systems, Protecting Buildings from Bomb Damage: Transfer of Blast-Effects
    Mitigation Technologies from Military to Civilian Applications
    (Washington, D.C.: 1995), pp. 28-29.

    At Muhammadiyat, DOD, using test data from Dugway Proving Ground, provided
    details about how source term characterizations for agent released were
    derived. However, the type and quantity of explosives used in the Dugway
    testing-and, therefore, the resulting effects-are not comparable with the
    type and quantity of munitions that were actually used at Muhammadiyat. At
    Dugway Proving Ground, small explosive charges were placed on boxed
    rockets; at Muhammadiyat, the munitions storage bunkers were targeted with
    multiple high-explosive bombs. Agent purity at Muhammadiyat was estimated
    at 15 percent. In addition, according to UNSCOM, there are many questions
    as to the accuracy of Iraqi records for the number of munitions filled
    with sarin at Muhammadiyat.

    Major Unresolved The major unresolved issues concerning DOD's modeling
    include

    assumptions about (1) CIA's modeling of Khamisiyah Bunker 73; (2)Issues
    Concerning repeated aerial bombings of storage facilities; (3) repeated
    aerial bombings Modeling of other storage, as well as research and
    production, facilities; (4) binary

    munitions and combustion by-products; and (5) detection of CW agents.

    CIA's Modeling Assumptions about Khamisiyah Bunker 73

    In July 1996, the CIA briefed the Presidential Advisory Committee on Gulf
    War Veterans' Illnesses on the results of its Bunker 73 model. In the
    August 2, 1996, report, identifying its modeling assumptions, the CIA
    concluded that any hazard area resulting from the demolition of Bunker 73
    had moved east and northeast.15According to CIA reporting, Bunker 73 and a
    number of other bunkers were destroyed on March 4, 1991. The pit,
    warehouses, and most of the remaining bunkers were destroyed on March 10,
    1991. The CIA revised some of the source term assumptions for Bunker 73 in
    its 2002 report, but Bunker 73 was never remodeled.16 Among the CIA's more
    significant assumptions in the 1996 modeling of the demolition of Bunker
    73 were these:

    o  	Bunker 73 contained approximately 1,060 rockets filled with sarin
    (this figure was modified to 910 rockets in 2002).

    o  Each rocket was filled with 8 kg of a 2:1 ratio of sarin to cyclosarin.

    15Central Intelligence Agency, CIA Report on Intelligence. 16Central
    Intelligence Agency, Intelligence Update.

    o  	The demolition ejected an estimated 10 percent of the rockets from the
    bunker.

    o  	U.S. tests showed that heat from the explosion, as well as burning
    motors and crates, degraded all but 2.5 percent of the agent in the
    bunker.

    o  Winds were light, northeast to east.

    o  	The modeling did not include the effect of thermal energy released by
    the simultaneous burning and detonation of the other 32 to 37 bunkers at
    the site.

    The models used to arrive at these conclusions, however, were not
    identified in the 1996 CIA report. According to the SAIC analyst who
    conducted this modeling, the models used, the NUSSE4 and DP2C, were
    dispersion models. (They were among the models that the IDA expert panel
    later evaluated as having been inadequate for assessing the pit.)

    In addition, the potential for greater contamination than indicated by the
    initial models exists, given (1) UNMOVIC's assertion that UNSCOM did not
    physically inspect this bunker through 1996 for safety reasons related to
    contamination and structural instability and given DOD's conclusion that
    all but 2.5 percent of the agent was degraded and (2) the lack of
    correlation between the igloo testing studies and actual events.

    Assumptions about Repeated Aerial Bombings of Storage Facilities

    DOD reported that the Al Muthanna storage, as well as research and
    production, facilities for CW agents was repeatedly attacked. Despite its
    repeated bombing, however, on only one occasion did the CIA and DOD
    express any concern about agent release. According to DOD analysis of the
    destruction of Bunker 2 at Al Muthanna on February 8, 1991, no trace
    residue from CW agents was detected in or around the bunker during UNSCOM
    inspections. However, UNMOVIC told us that UNSCOM never inspected this
    bunker for safety reasons. A low-level vapor hazard, however, probably
    emanating from damaged and leaking 122 mm rockets stored in the open, was
    detected around some of the other facilities. UNSCOM also reported
    contamination in several other facilities at Al Muthanna that produced CW
    agents. These observations suggest that additional releases may have
    resulted from the repeated attacks at this site. However, DOD did not
    analyze or model additional direct or incidental destruction from the
    numerous bombings at the site.

    There were 17 discrete Coalition aerial bombings of the Muhammadiyat
    munitions storage facility. For Muhammadiyat models, we identified two
    issues: time for agent dissipation and number of aerial bombings. For
    agent dissipation, DOD assumed that agent concentration would have been
    reduced to miniscule amounts during the first 24 hours. Therefore, for
    this model, DOD chose a duration of 24 hours.

    For number of aerial bombings, DOD made the assumption that all sarin at
    Muhammadiyat was released at one time; therefore, DOD modeled each aerial
    bombing as if it were the only bombing that caused a release. According to
    DOD, each model produced a freeze frame of the largest hazard area. The
    models suggest that the hazard area grows until it reaches its maximum
    size, which is about 10 to 12 hours after the release. However, in these
    models, DOD focused on a single bombing, failing to consider the
    cumulative effects of exposure resulting from multiple aerial bombings.

    Assumptions about Repeated Aerial Bombings of Other Storage, as Well as
    Research and Production, Facilities

    CW agents could have been released from a number of suspected storage
    sites targeted for Coalition bombing, in addition to Al Muthanna and
    Muhammadiyat. As shown in table 2, the intelligence community identified
    numerous sites alleged to include research, production, or storage
    facilities for CW agents. Another element of uncertainty in the modeling
    site selection process results from the possibility that low-level
    chemical agent exposures might have originated from bombing these other
    sites during the Gulf War. Many of these sites were entirely discounted
    for the purposes of the CIA's and DOD's models because the intelligence
    community's assessment was that potential plumes from these sites could
    not have reached U.S. troops.

    Table 2: Gulf War Suspected Chemical Weapon Sites

           Site type         Site name and place          Site name and place
           Facility         Al Muthanna (Samarra)     Fallujah III (Habbaniyah I)
                         Fallujah I (Habbaniyah III)   Khamisiyah (Tall al Lahm)
                         Fallujah II (Habbaniyah II)       Muhammadiyat (Qubaysah
                                                                   Storage Depot)
    Airbase, airfield  Al Bakr Airfield (Samarra     Murasana Airbase (H3 NW
                                East Airfield)                 Airfield)
                          Al Taba'at Airstrip (H3 SW  Qadisiyah Airbase (Al Asad
                                  Airfield)                    Airfield)
                             Al Taqaddum Airfield       Qayyarah West Airfield
                             Al Tuz Airfield (Tuz        Saddam Airbase (Qayyarah
                              Khurmatu Airfield)                   West Airfield)
                             Al Walid Airbase (H3           Tallil Airfield
                                  Airfield)
                                 K-2 Airfield         Tammuz Airbase (Al Taqaddum
                                                                        Airfield)

             Kirkuk Airfield Ubaydah Bin al Jarrah Airfield Mosul Airfield

    Ammo Ad Diwaniyah Ammo Depot Kirkuk Ammo Depot West

    Al Fallujah Ammo Depot South 	Qabatiyah Ammo Storage (Wadi al Jassiyah
    Ammo Storage)

    An Nasiriyah Ammo Storage Depot SW Qayyarah West Ammo Storage Depot

             Ash Shuaybah Ammo Storage Depot Tikrit Ammo Depot (Salahadin)

    Baghdad Ammo Depot Taji Ukhaider (Karbala Depot and Ammo Storage)

    Other Al Qaim Superphosphate Fertilizer Plant 	Fallujah Chem Proving Gnd
    (Habbaniyah CW Training Center)

    Dujayl/Awarah (Sumaykah SSM Support Facility SE)

    Source: Central Intelligence Agency, CIA Report on Intelligence Related to
    Gulf War Illnesses (McLean, Va.: Aug. 2, 1996).

    Assumptions about Binary During our interview with UNSCOM and UNMOVIC
    officials, we were

    Munitions and Combustion informed that Iraq had extensively deployed
    binary CW munitions

    By-Products 	components at a number of sites within range of the theater
    of operation. The chemical munitions were deployed unfilled but with
    chemical components that when mixed would make the nerve agent sarin.
    While there is no evidence that Iraq used these munitions offensively, it
    remains unknown whether these materials were mixed intentionally or
    inadvertently during combat engagements. In addition, Iraq declared that
    823 metric tons of CW agent precursor materials, deployed throughout Iraq,
    were destroyed during the Gulf War. The hazards associated with
    environmental fallout from the destruction of these materials remain
    unknown. CIA assessments and DOD modeling specifically did not address
    potential exposure to binary CW agents, exposure to CW agent precursors,
    or the hazardous environmental consequences associated with the

    combustion by-products of sulfur mustard from the bombings at Muhammadiyat
    and other sites.17

    Assumption about the Detection of CW Agents

    Credible scientific evidence suggests that the reported detections of CW
    agents were reliable. These detections, during the early phases of the air
    war, included the use of an array of scientific methods. The CIA and DOD
    assert that the various detections are not valid because the source of the
    agents cannot be detected. Available evidence, however, can explain the
    detections and suggests that troop exposure may be far more widespread
    than that projected from the CIA and DOD modeling of the Khamisiyah
    release alone.

    Coalition forces possessed a diverse array of CW detection and
    identification equipment. Czechoslovak chemical detection troops also used
    Warsaw Pact equipment, such as the GSP-1, GSP-11, and Czech mobile
    chemical agent laboratories. This broad array of equipment included
    various technologies to detect and confirm the presence of CW agents, as
    well as to identify specific agents. The different physical principles
    that were employed included wet chemistry, mass spectrometry, ion mobility
    spectrometry, chemical reaction, biochemical enzyme reactivity, flame
    photometry, and ionization. Detector (that is, sensor) and agent
    identification systems that Coalition forces deployed, reporting the
    detection of CW agents, are shown in table 3.

    17Precursors are chemicals and other materials used in producing CW agents

    Table 3: Detector and Agent Identification Systems Deployed by Coalition
    Forces Reporting the Detection of CW Agents

    Nation System Chemical agent Sensitivity Method or technology
    Czech Automatic Nerve Agent G-and V-series nerve agents 0.05 mg/m3 Air
    sampling, biochemical enzyme

    Republic

    Detector Alarm GSP-11

                    (cholinesterase reactivity) 0.1 mg/m3 2.0 mg/m3

              Mobile Laboratory Most CW agents  Agent           Field portable
              CHP-71,                           identification  chemical agent
                PCHL-90, and                                          laboratory,
                   PCHL-90                        through wet            chemical
                                                                        reagents,
                                                chemistry         wet chemistry
                                                analysis            analysis
    France    Detalac F1      G-and V-series  Not available  Biochemical
                                   nerve agents                 enzyme detector
              Chemical                                                   Chemical
              Detection Control   Tabun/sarin                         biochemical
                                    (GA/GB)         1 mg/m3              detector
                 Kit (TDCC)        Hydrogen        350 mg/m3
                                 cyanide (AC)
                                   Cyanogen       2000 mg/m3
                                 chloride (CK)
              Chemical
              Detection Unit      Sarin/soman    Not available        Flame
              for                   (GB/GD)                       spectrometry
              Fixed
              Installations
              (ADLIF)

                Chemical Agent  G-and                           Ion mobility
    United      Monitor      V-series       0.1 mg/m3        spectrometry
                                nerve agents
    Kingdom                     Blister     2.0 mg/m3   (quantitative feature)
                                 agents (H)
                 Nerve Agent      G-series                     Biochemical enzyme
                 Immobilized    nerve agents   0.05mg/m3                 detector
               Enzyme Alarm and   V-series    0.005 mg/m3     (cholinesterase
               Detector         nerve agents                    reactivity)
                   (NAIAD)
                    MARK I        G-series        Not        Biochemical chemical
                                nerve agents   available               reactivity
                                   Blister
                                 agents (H)

    United    M8A1 Alarm    G-series nerve 0.1 mg/m3         Ionization
                                   agents
    States                  V-series nerve 0.2 mg/m3      Automatic alarm
                                   agents
                M8 Paper; M9   G-and V-series
                   Paper       nerve agents     Yes/no     Chemical reactivity
                               Blister agents   Yes/no     Color interpretation
                                    (H)
              Chemical Agent   G-series nerve                  Biochemical enzyme
              Detector Kit         agents     0.05 mg/m3                 detector
              M256 and M256A1  V-series nerve 0.15 mg/m3 (cholin-esterase
                                   agents                reactivity)
                               Blister agents 3.0 mg/m3    Chemical reactivity
                                    (H)
               Chemical Agent  G-and V-series
                  Monitor      nerve agents
                               Blister agents
                                    (H)

    Ion mobility spectrometry (quantitative feature)

                MM1 FOX NBC vehicle G-series nerve agents Several mg/m3

    Quadrapole gas chromatography
    C-mass spectrometryS
    Full GC-MS

    60 other preprogrammed agent spectra

    M8A1 (M43) ionization backup unit (early warning)

    Sources: DOD FM Series 3; Chemical Research, Engineering, and Development
    Command, Aberdeen Proving Grounds, Md.; manufacturers; Jane's NBC
    Protection Equipment (1991-92 and 1995-96); CIA, Chemical Warfare Agent
    Issues during the 1991 Persian Gulf War (Apr. 2002); video footage of
    Czech chemical detection unit activity during the 1991 Gulf War; Czech
    Chemical Warfare Report, Intelligence Assessment of Chemical and
    Biological Warfare in the Gulf, prepared by U.S. Army Foreign Science and
    Technology Center and DIA for the Defense Science Board investigating the
    Desert Storm Syndrome.

    Shortly after the air war began, the period between January 18 and January
    23, 1991, was marked by a stationary frontal pattern and the development
    of low-level cloud and fog activity directly over the areas occupied by
    Coalition forces. Figure 3, based on NOAA-11 AVHRR 1B meteorological
    imagery, shows contemporaneous visual evidence of this anomaly.

    Figure 3: NOAA-11 Meteorological Imagery of Areas Occupied by Coalition
    Forces, January 18-24, 1991

    Source: NOAA.

    Note: NOAA-11 AVHRR 1B meteorological imagery, processed by Earth
    Satellite Corporation, Rockville, Md., was obtained from the National
    Center for Atmospheric Research, Ashville, N.C.

    During this prolonged period, a significant number of reported CW agent
    detections were reported in northern Saudi Arabia where Coalition forces
    were deployed (see table 4).

    Table 4: Principal Reported Detections of Chemical Agents in Saudi Arabia,
                                  January 17-23, 1991

        Date   Nation and unit    Place        Agent       Method or technology
                                             detected
    Jan. 17 United States   NW Hafir Al Unknown nerve Ionization, biochemical
               2/5TH SFG       Batin           agent     reaction; ion
                                                         mobility spectrometry;
                                                         M8A1, M256,
                                                                   CAM
    Jan. 19 Czech Republic  N Hafir Al                 Biochemical reactivity;
               Chemical           Batin     Sarin (GB)             wet chemistry;
               Detection Unit                             GSP-1(11), mobile lab
                               NE Hafir Al                Biochemical reactivity;
                               Batin        Sarin (GB)             wet chemistry;
                                                          GSP-1(11), mobile lab
                               King Khalid Unknown nerve  Biochemical reactivity;
                               Military        agent               wet chemistry;

                           City (KKMC) GSP-1(11), mobile lab

              France        30 km from  Unknown nerve    Biochemical reactivity
                            KKMC            agent
          Czech Republic    30 km from Confirm French
             Chemical       KKMC          detection     Wet chemistry mobile lab
          Detection Unit
                               KKMC    Sulfur mustard   Wet chemistry mobile lab
                                            (HD)
                                       Unknown blister Chemical reactivity; ion
          United Kingdom      Jubayl       (after      mobility
                                         unexplained     spectrometry; M-9, CAM
                                         explosions)
        United States 24th             Unknown blister Chemical reactivity; M-256
              Naval           Jubayl       (after                     (2/3 tests)
    Reserve Construction              unexplained
                                         explosions)
    Battalion (Seabees)

    Jan. 20	Czech Republic Chemical Near KKMC Sulfur mustard (HD) for Wet
    chemistry mobile lab Detection Unit 2 hours

    French sector Sarin (GB)/tabun (GA) Biochemical reactivity; wet chemistry
    KKMC mobile lab

                   France      Near KKMC    Unknown nerve        Biochemical
                                                agent            reactivity
                United States                                    Ionization,
                  800th MP     NW of KKMC   Unknown nerve        biochemical
                                                agent            reactivity;
                     BDE                                         M8A1, M256
                                 Dharan   Unknown nerve          Biochemical
               United Kingdom             agent (after      reactivity (separate
                                            SCUD attack)      devices); NAIAD,
                                                                    MARKI
                                                                      Biochemical
    Jan. 21 Czech Republic     KKMC     Sarin (GB)/tabun       reactivity; wet
               Chemical                        (GA), sulfur             chemistry
               Detection Unit               mustard (HD)         mobile lab
                   France         KKMC      Unknown nerve        Biochemical
                                                agent            reactivity
                                                            Chemical or
                                  KKMC                      biochemical
                                          Unknown CW agent  reactivity

    Jan. 22 United States RAFHA Unknown nerve agent 	Ionization, biochemical
    reactivity; M8A1, M256

    Jan. 23	Czech Republic Chemical KKMC Unknown CW agent Wet chemistry mobile
    lab Detection Unit

    Near KKMC Patch of sulfur mustard (HD) Wet chemistry mobile lab

    Sources: CENTCOM CCJ3-X log (partially declassified 1995), Defense Science
    Advisory Board report (June 1994), Czech government reports on detection
    activity during the Gulf War, and declassified Defense Intelligence Agency
    reports on chemical detection activity.

    This period of reporting on chemical agent detection is attributable to
    the use of many of the instruments and methodologies cited in tables 3 and
    4 and coincides directly with the initial Coalition bombings of confirmed
    and suspected Iraqi CW research, production, and storage facilities during
    January 17-24, 1991.

    That these detections were reported raises continued and unresolved
    concern that U.S. troop exposures may have been more frequent and more
    widespread than the CIA and DOD believe. In addition, these exposures may
    have involved different populations than can be assumed from the limited
    simulations performed with the CIA and DOD models we refer to in this
    report. For example, figure 4 shows NOAA-11 collected infrared satellite
    imagery data for January 19, 1991, that NOAA published, indicating a line
    of instability and an inversion coincident with, and possibly
    precipitating, the detection of CW agents in the vicinity of Hafir al
    Batin and King Khalid Military City, reported by Czech chemical detection
    units and other Coalition units in the region (as shown in table 4).

         Figure 4: Meteorological Satellite Photography, Iraq, January 19, 1991

         Muhammadiyat  Fallujah               Muthanna Baghdad
                                              Ukhaider
                                    (Karbala Depot and
                                              Storage)
                                                                    Khamisiyah
                          Rafha
                                                                Hafir al Batin
                                                                   King Khalid
                                                                 Military City

                           Source: GAO analysis of NOAA data.

    The lighter areas in the image represent warmer air, the darker areas
    colder air. In the image, a collision is shown between cold and warm air
    masses, as well as what appears to be evidence of inversion activity. That
    is, colder upper air moves below the warmer air, which is normally closer
    to the surface, possibly precipitating the detections.

    The assessment by the CIA that the detections of the Czech chemical
    detection units are not credible-despite earlier DOD technical assessments
    that Czech detections of sarin and mustard agent on two occasions were
    credible-are unsound because these assessments do not refute the
    underlying scientific evidence, according to DOD and DIA

    18

    experts.

    The presence of both sarin and mustard agents at subacute levels, and in
    such close proximity, could reasonably be explained as the result of
    fallout from Coalition bombings of Iraqi weapons facilities and storage
    bunkers. This possibility is supported not only by the atmospheric data
    but also by observing that the Czech nerve agent detections were made,
    according to DIA reporting, by multiple teams over a range of 20 to 50 km,
    within 30 minutes of one another, during a strong weather inversion.19
    According to U.S. reporting, during the period immediately before the
    detections, the following known Iraqi CW agent research, production, and
    storage sites (with geocoordinates and dates) were bombed:

    o  Al Muthanna (3350 N, 04348 E, January 17, 1991),

    o  Al Nasiriyah (3058 N, 04611 E, January 17, 1991), and

    o  Qabatiyah (3353 N, 04239 E, January 19, 1991).

    In addition, production sites for CW agent precursors were bombed during
    this period.20 The potential remains that sites that may have been
    incorrectly assessed as not containing CW agents were also bombed

    18See Czech chemical warfare report, Intelligence Assessment of Chemical
    and Biological Warfare in the Gulf, prepared by the U.S. Army Foreign
    Science and Technology Center and DIA for the Defense Science Board
    investigating Desert Storm Syndrome.

    19Defense Intelligence Agency, Detection of Chemical Warfare Agents by
    Czechoslovak Unit during Desert Storm, Part III (U), IIR 6 284 0008 94
    (Washington, D.C.: Oct. 14, 1993).

    20U.S. Army Operations Group, UNSCOM, Inspection of Chemical Warfare
    Facilities, IIR 2 201 0022 92 (Washington, D.C.: Oct. 3, 1991,
    declassified 1995).

    during this period. These activities may have resulted in additional
    releases of CW agents.

    In this section, we discuss our findings about DOD's modeling efforts in
    more detail, explaining the ways in which we believe them to be lacking in
    credibility.

    DOD's Modeling

    Efforts Were Flawed

    DOD's Models Significantly Underestimated Plume Height

    Actual plume height might have been significantly higher than the height
    DOD estimated from its models of demolition operations and bombings, given
    the assumptions DOD's modeling used for Khamisiyah and the other Iraqi
    storage facilities. The plume height estimates that the CIA provided for
    demolition operations at the Khamisiyah pit were 0 to 100 meters. However,
    neither the CIA nor DOD conducted testing to support estimated plume
    height associated with the bombings of Al Muthanna, Muhammadiyat, or
    Ukhaydir. According to DOD modelers, neither plume height nor any other
    heat or blast effects associated with these bombings were calculated;
    instead, these data were taken from DOD's Office of the Special Assistant
    for Gulf War Illnesses.

    In addition, according to a principal DTRA modeler, DOD's data on plume
    height were inconsistent with other test data for the types of facilities
    bombed. This expert cited test studies conducted at White Sands Proving
    Ground demonstrating that plume height would range from 300 to 400 m. The
    CIA maintains, however, that the plume occurred near ground level because
    there was no altitude, burst of munitions, or any kinetic force such as
    bomb blast to force the agent to become airborne initially. DOD maintains
    that during the bombing of chemical agents, liquid agent absorbs the
    energy of the blast, greatly reducing plume heights. We asked the CIA and
    DOD to provide test data in support of their assertions but neither agency
    provided any evidence.

    Modeling experts from LLNL who participated in only the initial modeling
    of the Khamisiyah pit site also said that they questioned the plume height
    estimates. In a prewar analysis, LLNL projected that the plume immediately
    following the bombing of Iraqi storage facilities for CW agents would be a
    surface-based plume with a horizontal radius of 54 m (177 ft.) and a
    height of 493 m (1,617 ft.). A 1969 Sandia National Laboratories empirical
    study established a power-law formula for calculating plume heights
    attributable to high-explosive detonations (see appendix II). By this
    formula, a conventional MK-84 or GBU-24 bomb (containing 942.6 lb.

    of high explosives) of the type used to bomb sites other than those at
    Khamisiyah would generate a plume of approximately 421 m.

    Impact by Weight of Explosive 	Figure 5 shows the trend line for a plume
    height predicted on the basis of the formula for calculating plume height
    resulting from detonating high explosives ranging from 100 to 2,000 lbs.
    in weight.

    Figure 5: Plume Height Trend Line by Weight of Explosive

    Height in meters 600

    500

    400

    300

    200

    100

    0

    100lb 500lb 1000lb 2000lb

    Weight of high explosives Source: GAO.

    According to DOD officials, the Sandia National Laboratories study is not
    accurate or scientifically valid because it did not account for weather
    effects. Further, they said, it based plume height on the detonation of
    conventional explosives, but the liquid agent of chemical-filled munitions
    would have absorbed much of the energy of the blast if these had been
    bombed; therefore, plume height would have been greatly reduced. However,
    DOD could not provide us with any data, studies, or testing of the
    explosive aspects and buoyancy of chemical agents to corroborate these
    observations.

    At Muhammadiyat, DOD established a plume height of 0.5 m (roughly half the
    bomb height) for nerve agent and a plume height of 1.0 m (roughly half the
    median height of the various bomb stacks) for mustard agent destroyed at
    this location. Moreover, according to one internal DOD memorandum, an
    "initial cloud size" of 10 m, in both lateral and vertical directions, was
    "arbitrarily" established. According to DOD, no effort was made to
    validate these estimates by analyzing video images that showed

    some of the plume data, such as (1) those taken from ground level at
    Khamisiyah and (2) the available footage from the aircraft and munitions
    used to bomb the other sites.

    Impact by Wind Speed	Figure 6 shows that disparity in source term data for
    plume height could lead to vastly divergent results as to how far the
    plume travels and disperses. This observation is particularly relevant
    during nighttime periods, when a stable nocturnal boundary layer emerges.

    Figure 6: Boundary Layer Characteristics

    Source: Roland B. Stull, An Introduction to Boundary Layer Meteorology
    (Boston, MA: Kluwer Academic Publishers, 1988), p. 11. Used with kind
    permission of Kluwer Academic Publishers.

    Figure 6 shows the stable nocturnal boundary layer where winds often
    accelerate to higher speeds, in a phenomenon referred to as the low-level
    or nocturnal jet-that is, winds are aloft in the nighttime hours. At
    altitudes on the order of 200 m above ground, winds may reach 10 m to 30 m
    per second (22 to 67.5 mph) in the nocturnal jet. Higher plumes than those
    DOD postulated, coupled with this phenomenon, could result in chemical
    agents being transported rapidly until disturbed by turbulence or the
    return of the mixed layer, some time after dawn. However, this possibility
    was not taken into consideration in any of the modeling DOD performed.
    Consequently, the models may have dramatically underestimated the extent
    of plume coverage.

    According to DOD, such winds are not known to be present in Iraq. DOD
    confirmed, however, that it has no available data on prevailing wind
    conditions in the region, over the varying terrain, or during the time
    period in question to rule them out. DOD also stated that data are not
    available for determining the presence of a low-level or nocturnal jet at
    the time of the Khamisiyah demolition. However, DOD acknowledged
    uncertainty as to whether a low-level jet was present on any specific date
    or at any specific location.

    Impact by Plume Geometry	According to plume geometry, the majority of
    plume mass associated with high-explosive discharges is located toward
    higher altitudes (see figure 7). This suggests that the majority of the
    plume mass would move to higher altitudes to be transported by higher wind
    speeds.

    Figure 7: Three Types of Plume Geometry

    Source: Department of Energy, Lawrence Livermore National Laboratory.

    Similarly, the distribution of plume geometry may be affected by nocturnal
    jets, as shown in figure 8.

    Figure 8: The Impact of Nocturnal Jets on a Plume at Higher Altitudes

    Source: Department of Energy, Lawrence Livermore National Laboratory.

    Empirical studies and observed events tend to refute the assumptions with
    which the CIA and DOD discounted the alternative assumption that the plume
    was transported by low-level jets. First, empirical testing suggests that
    the plume heights were much higher than postulated in the source term
    data. Second, no massive casualties or effects were claimed, reported, or
    observed in areas immediately surrounding the Iraqi CW research,
    production, and storage facilities bombed by Coalition forces. In the
    absence of an alternative explanation, acute effects should have been
    observed in areas near the bombed sites.

    Third, since many of the bombings were at night, the explosive effects-
    coupled with higher-altitude plumes and a nocturnal boundary layer capable
    of moving hazardous materials hundreds of miles-could easily account for
    the phenomena reported above. These effects could also account for the
    numerous reports of CW agents detected in sites occupied by U.S. and
    Coalition forces. Fourth, these effects may account for reported nighttime
    detections of low levels of CW agents, associated with
    turbulence-resulting from aircraft-related sonic booms and incoming
    missiles and artillery-mixing the upper-level and lower-level atmospheric
    layers.

    DOD's Field Testing Did Not Realistically Simulate Actual Conditions

    Demolition and Bombing Simulations Were Not Realistic

    Extrapolation Data Contained Acknowledged Limitations

    To simulate the effects of demolition on chemical nerve agent stockpiles,
    the CIA and DOD conducted postwar field testing at Dugway Proving Ground.
    They explored what percentages of agent would be deposited on the ground
    as a liquid, consumed by the demolition, and aerosolized. To obtain these
    source term data for their models of Khamisiyah, the Dugway Proving Ground
    testing center conducted seven field tests and two laboratory studies from
    May 1997 through November 1999.

    For field testing to be effective, conditions have to be as close to the
    actual event as possible, but these tests did not provide more definitive
    data for the CIA's and DOD's models. The tests did not realistically
    simulate the conditions of the demolition of 122 mm chemical-filled
    rockets in Khamisiyah. The simulations took place under conditions that
    were not comparable with those at Khamisiyah. There were differences in
    meteorological and soil conditions; the construction material of munitions
    crates; rocket construction (including the use of concrete-filled pipes as
    rocket replacements to provide inert filler to simulate larger stacks);
    and the numbers of rockets, using far fewer rockets and, therefore,
    explosive materials. Additionally, the tests used an agent stimulant whose
    physical properties differed from those of the actual agent.

    For example, of the 32 test rockets with simulant-filled warheads, a small
    sample was used to conduct all seven field tests: five tests were
    singlerocket demolitions and two involved multiple-rocket demolitions. One
    multiple-rocket field test demolition used 9 functional rockets plus 3
    dummy rockets; the other multiple-rocket field test used 19 functional
    rockets and 5 dummy rockets. In contrast, at the Khamisiyah pit, stacks of
    122 mm rockets were detonated, estimated at about 1,250 rockets. Dugway
    officials acknowledged that detonating a larger number of rockets would
    have made a significant difference to the testing. In addition, aerial
    bombing with a heavy explosive load, such as had occurred at the sites
    other than Khamisiyah, would have had a far greater effect than was
    achieved with the Dugway testing.

    According to DOD officials, SAIC developed projection data, in support of
    the Dugway tests, to extrapolate the results to the larger stockpiles
    identified at Khamisiyah. However, in our review of these data, we found
    that the SAIC analysts acknowledged limitations to their study. They noted
    in their report:

    Testing Did Not Use Iraqi Soil and Wood

    This is the first attempt to develop an understanding of these processes
    and we lack sufficient data to either validate or completely calibrate our
    models. The models in many cases have diverged from first principles
    models and have become "engineering" models in the sense that explicit
    calculations have been based on the observations of others and these have
    not been well documented as yet. In some cases, it may be that further
    calculations and/or tests will determine that for different configurations
    than those calculated/tested, some of the understandings developed from
    examining the existing data

    21

    may have to be modified.

    Finally, SAIC acknowledged that calculations were performed in two
    dimensions, stating that full, three-dimensional calculations were not
    feasible.22

    SAIC's conclusion was that the test explosions did not produce gases
    likely to endure long enough to cook off-that is, ignite-a motor, even in
    a large stack. But SAIC pointed out that "the real world often holds
    surprises in chaotic situations of this sort." For example, if a rocket
    motor were to ignite and burn in place, its energy might sensitize
    adjacent motors or cause cook-off initiation: "these processes could walk
    their way through the aisles [stacks] with minutes between dramatic
    events."23 The potential for real world events like these points to the
    inadequacy of attempting to extrapolate from the small-scale controlled
    testing at Dugway Proving Ground to the large-scale and relatively
    uncontrolled conditions at Khamisiyah.

    According to DOD and CIA analysts, the type of soil and wood can have a
    significant effect on the dispersion of the agent. Their estimates of the
    evaporation and retention rates of the chemical agent spilled on the soil
    may not be similar to what actually evaporated from and was retained in
    the pit sand at Khamisiyah. Although Iraqi soil was available and used in
    the laboratory testing, it was not used in field testing. Similarly,
    assessments of DOD and CIA estimates of the amount of spilled agent
    evaporated from and retained in wooden crates are uncertain. This is
    because Dugway testing officials could not obtain actual wood from the
    Khamisiyah pit site. The aged and possibly damp wood at Khamisiyah

    21G. I. Kent and others, Interim Report: Calculations and Measurements in
    Support of the Rocket Testing at Dugway Proving Ground (Dugway, Utah: June
    17, 1997), p. 2.

    22Kent and others, Interim Report: Calculations and Measurements, p. 2.

    23G. I. Kent and others, Interim Report: Rocket Motor Ignition/Explosives
    Issue (Dugway, Utah: June 17, 1997), p. 15.

    might have absorbed less agent than the new wood used at Dugway. DOD and
    CIA determined that only about 32 percent of the agent was released and
    that most leaked into the soil and wood, with 18 percent of the leakage
    becoming part of the plume (2 percent through aerosolization and 16
    percent through evaporation).

    Field tests were also conducted at a time of year and time of day
    different from the actual Khamisiyah pit event. According to Dugway
    officials, testing was done in May and in the early morning hours, when
    drainage conditions prevail.24 When the March 10, 1991, U.S. demolition
    operations took place at the Khamisiyah pit, it was late afternoon with a
    mixed layer. The bombings of the other modeled storage and production
    sites often took place during evening and nighttime hours, when a stable
    nocturnal boundary layer emerges.

    Despite the uncertainties in approximating the conditions at Khamisiyah,
    DOD and the CIA used these data not only for modeling Khamisiyah but also
    for modeling other sites. At the other sites, the CW munitions would have
    been destroyed by aerial bombings with much greater quantities of
    high-explosive charges and under significantly different meteorological
    conditions.

    All Models, Including DOD's Composite Model, Showed Divergent and
    Unresolved Results

    The models DOD used to predict the fallout from Khamisiyah and the other
    sites showed great divergence, even with the same source term data. While
    the models' divergences included plume size and path, DOD made no effort
    to reconcile them (see appendix III). The IDA expert panel determined that
    the results were so divergent that it would not be possible to choose the
    most exposed areas or which U.S. troops might potentially have been
    exposed. IDA therefore recommended a composite model, which DOD adopted.25
    However, this approach masked differences in individual model projections
    with respect to plume size and path.

    24Drainage winds, also called mountain or gravity winds, are caused by the
    cooling air along the slopes of a mountain. Drainage wind periods were
    intentionally chosen for Dugway testing to minimize the dispersion of the
    test materials to the surrounding areas. According to Dugway officials,
    these winds are common to Dugway Proving Ground in the morning before the
    development of the mixing layer.

    25The composite approach DOD used is also known as the ensemble approach.

    In addition, DOD chose not to include in the composite model the results
    of the LLNL model, created at the IDA expert panel's request, which showed
    a different and larger plume size and path than DOD's models showed. The
    IDA panel regarded the LLNL model as less capable than other models
    because it modeled atmospheric phenomena with less fidelity. Finally,
    modeling of Khamisiyah that the Air Force Technical Applications Center
    (AFTAC) had done also showed differences from DOD's composite model.

    LLNL's Model 	To determine plume size and path, LLNL conducted analyses
    using DOE's MATHEW meteorological model with the ADPIC dispersion model.
    During LLNL's presentations to the IDA panel in November 1996 and February
    1997, LLNL provided a 72-hour projection, assuming an instantaneous
    release of the contents of 550 rockets containing sarin (see figure 9).
    The results of LLNL's analyses show the plume covering an area extending
    south southeast from the release point to the Persian Gulf, then turning
    eastward at the Gulf coast, and then turning northeast over the Gulf and
    extending northeastward across central Iran.

    Figure 9: Lawrence Livermore National Laboratory Projection

    Source: Department of Energy, Lawrence Livermore National Laboratory.

    LLNL's modeling assessment showed that the 72-hour exposure projection-for
    the instantaneous release of sarin from 550 rockets- covered a large
    hazard area. According to LLNL, 2,255 sq km were covered

    by agent concentration in excess of the dosage expected to cause a person
    minimal effects.26 This area extended approximately 130 km south southeast
    from the release point. Dosages in excess of the amount that would be
    allowed for a worker exposed to sarin in the workplace, the occupational
    limit, were predicted over 114,468 sq km-including Kuwait City, an area
    approximately 200 km wide across the Persian Gulf, and the higher
    elevations of the Zagros Mountain range of western Iran.27 The remaining
    area was determined to be at the general population limit.28

    DOD's Composite Model 	DOD's composite model was based on OMEGA and COAMPS
    meteorological models and HPAC/SCIPUFF and VLSTRACK dispersion models. In
    contrast to LLNL's modeling simulations, it showed the plume moving first
    southerly and then turning to the west southwest. The 72-hour plume
    overlay for DOD's composite model, resulting from using the VLSTRACK and
    HPAC/SCIPUFF dispersion models with COAMPS and OMEGA meteorological
    models, is shown in figure 10.

    26"Minimal effect" is the lowest concentration expected to have noticeable
    effects on human beings.

    27"Occupational limit" is about one-tenth of the minimal effects value and
    the maximum concentration level that would be allowed for a worker who
    could become exposed to sarin in the course of performing job duties.

    28"General population limit" represents the limit below which any member
    of the general population could be exposed-by, for example, exhaling-7
    days a week, every week, for a lifetime without experiencing any adverse
    health effects.

      Source: Department of Defense, Office of the Special Assistant for Gulf War
                                        Issues.

                         Page 41 GAO-04-159 Gulf War Illnesses

    Composite modeling may be an appropriate methodology, but DOD's composite
    model understated the number of troops potentially exposed by not
    including the LLNL model. If LLNL's model were included, a far larger
    number of forces would potentially be shown as having been exposed (see
    figure 11). DOD's exclusion of this model seriously skewed the outcome of
    any epidemiological studies done thus far.

    Source: GAO analysis of Department of Defense and Department of Energy,
    Lawrence Livermore National Laboratory, models.

                         Page 43 GAO-04-159 Gulf War Illnesses

    Explaining the Models' Divergent Results

    Further research was conducted to determine whether the models' divergent
    results could be explained. It was observed that the divergence in the
    modeling outcomes could be explained by a directional split-a line of
    diffluence-in the independently modeled 10 m wind field data near
    Khamisiyah in the first 2 days of the modeling period. While the precise
    location of this line is critical in determining which way the wind would
    have transported the CW agent, its precise location cannot be resolved
    with any degree of certainty. (Appendix IV illustrates this diffluence
    with three different data sets.)

    In addition, DTRA officials said at the time of the modeling that they had
    conducted data-validation analyses of the various models against visible
    smoke plumes from the oil well fires in Kuwait. These analyses indicated a
    definite directional bias, shown in figure 12. This validation
    demonstrates that the actual area covered could have been from 10 to 50
    degrees to the east and could have affected a different population from
    that indicated by the model results.

                      Figure 12: Validation Runs of Various Models

    COAMPS MM5 OMEGA Visible plume VLSTRACK HPAC HPAC

    Source: GAO.

    aEast bias compared with OMEGA/HPAC. bEast bias compared with MM5/HPAC.
    cEast bias compared with COAMPS/VLSTRACK.

    In addition, in the 1997 DOD peer review panel report on the Khamisiyah
    models, a panel of experts in meteorological and turbulent diffusion
    modeling stated that the VLSTRACK and SCIPUFF/HPAC results were
    complicated by the use of significantly different source term inputs.29
    According to DOD, the 2000 modeling used a consistent source term for
    SCIPUFF and VLSTRACK. For VLSTRACK, internal source algorithms had been
    used, while for SCIPUFF, source term inputs from the Dugway experiments
    had been used. These differences would lead to significant divergences in
    the dosage contours the two models predicted, which were then used to
    generate the composite.

    In addition, the panel noted, while using a composite model is a valid
    method, successfully applied to other atmospheric modeling problems, using
    a composite model to reconstruct the dosage requires more advanced,
    state-of-the-art, high-resolution models, with the fewest physical
    limitations and assumptions. Furthermore, in 1998, the Air Force Human
    Effectiveness Directorate at Wright-Patterson Air Force Base reviewed the
    Muhammadiyat modeling and found that the work may have been flawed.
    According to the Chief of the Human Effectiveness Directorate, the
    protocol was not correct in that it constituted a "plume of plumes, rather
    than a plume based upon data."

    AFTAC Modeling 	AFTAC modeling of Khamisiyah also showed differences from
    DOD's composite model. After DOD's Khamisiyah models were published in
    1997, the Senate Committee on Veterans' Affairs asked AFTAC to conduct an
    analysis of the event.30 AFTAC is a principal modeling agency for DOD and,
    according to experts, the quality of its modeling system is among the
    highest. To conduct the analysis, AFTAC meteorologists used four models

    29Richard A. Anthes and others, "Comments by Review Panel on Khamisiyah
    Modeling Report and Presentations on November 4-5, 1997," report for the
    Directorate for Deployment Health Support of the Special Assistant to the
    Under Secretary of Defense (Personnel and Readiness) for Gulf War
    Illnesses, Medical Readiness, and Military Deployments, Fairfax, Virginia,
    December 11, 1997.

    30In early 1997, the Senate Committee on Veterans' Affairs established a
    Special Investigation Unit on Gulf War Illnesses to conduct a bipartisan
    review of the U.S. government's response to the unexplained illnesses
    suffered by veterans of the Gulf War. The year-long effort produced a
    detailed report on the actions by DOD before and during the war and by VA
    in its aftermath, relating to the current health of Gulf War veterans. See
    Arlen Specter, William F. Tuerk, and James R. Gottlieb, Report of the
    Special Investigation Unit on Gulf War Illnesses, U.S. Senate, Committee
    on Veterans' Affairs (Washington, D.C.: U.S. Government Printing Office,
    1998).

    from their suite of atmospheric models, including two primary transport
    and diffusion models and the RAMS meteorological model.

    While AFTAC's analysis was meteorologically consistent with the modeling
    efforts of the CIA and DOD, the results showed that some additional areas
    might have been exposed to at least low-level exposure dosages from the
    Khamisiyah plume. In particular, it showed the plume differing in several
    aspects from the plumes generated by the DOD and CIA analyses. Most
    significantly, the AFTAC plume is shown drifting across Kuwait and the
    northwestern Persian Gulf coast, an area not covered by the DOD and CIA
    plume. AFTAC's analysis was published in a report to the Senate Committee
    on Veterans' Affairs and was provided to DOD's Office of the Special
    Assistant to the Deputy Secretary of Defense for Gulf War Illnesses.31 The
    report recommended that AFTAC's results be integrated into the DOD and CIA
    modeling results to depict these additional areas of potential exposure.

    However, in 1998, a DOD expert panel reviewed the AFTAC modeling
    simulations and recommended that AFTAC's modeling results not be included
    in DOD's composite plume model, given that (1) AFTAC's simulations were
    generally consistent with DOD's composite model results and that the
    effect of any differences would only have resulted in the additional
    notification of a small number of individuals, (2) continuing to refine
    DOD's modeling process rather than including AFTAC's modeling results
    would be the best use of DOD's resources, and (3) the decay capability of
    the agent in AFTAC's model was still immature and would have limited any
    efforts to identify potentially exposed individuals.

    31U.S. Air Force, Technical Applications Center, Report on Atmospheric
    Modeling of the 10 Mar 91 Chemical Warfare Agent Release at the Khamisiyah
    (Iraq) Munitions Pit

    (Patrick Air Force Base, Fla.: Dec. 15, 1997).

    The MOD Relied on U.S. Plume Modeling to Determine Its Troops' Exposure to
    CW Agents

    Total U.S. Plume-Modeling Costs

    According to British officials, the MOD did not collect any source term or
    meteorological data during the Gulf War. It also did not independently
    model the plume from Khamisiyah, relying instead on the 1997 DOD and CIA
    modeling of Khamisiyah. According to British MOD officials, however, they
    were reassessing the extent of British troops' exposure, based on DOD's
    revised 2000 remodeling of Khamisiyah. We requested from the British MOD
    but did not receive information on the findings from this reassessment.

    Responding to parliamentary concerns and questions raised in 1997, the
    British MOD reviewed the U.S. modeling of demolition operations at
    Khamisiyah, publishing a report in December 1999.32 The MOD concluded from
    the 1997 DOD and CIA composite model of the Khamisiyah demolitions that
    the maximum concentration of agent that British troops might have been
    exposed to was below the level that the most sensitive British warning
    device could have been expected to detect. Moreover, according to the MOD,
    the highest theoretical dosage troops received would have been 3.6 times
    lower than the level at which the first noticeable symptoms occur.
    Finally, the MOD said, this level of exposure would have had no detectable
    effect on health.

    The MOD also determined that a number of British troops were within the
    boundary of the plume in the DOD and CIA composite model, and it estimated
    that the total number of British troops potentially exposed was about
    9,000. The total number of troops definitely within the path of the plume,
    however, was estimated to be about 3,800. In addition, of 53,500 British
    troops deployed, at least 44,000 were definitely not within the path of
    the plume. However, since the MOD relied exclusively on DOD's modeling and
    since we found that DOD could not know who was and who was not exposed,
    the MOD cannot know the extent of British troops' exposure.

    The CIA and DOD were the primary agencies in the modeling and analysis of
    U.S. troops' exposure from the demolition at Khamisiyah and bombing of
    chemical facilities at Al Muthanna, Muhammadiyat, and Ukhaydir, but
    several other agencies and contractors also participated. Funding to

    32"Review of Events Concerning 32 Field Hospital and the Release of Nerve
    Agent Arising from U.S. Demolition of Iraqi Munitions at the Khamisiyah
    Depot in March 1991," December 1999.

    support the modeling efforts was provided to various DOD agencies and
    organizations, the military services, and non-DOD agencies and
    contractors. We collected data on the direct costs these agencies incurred
    or funds they spent. Table 5 shows direct costs to the United States for
    modeling the Gulf War of about $13.7 million.

               Table 5: U.S. Direct Costs for Modeling Gulf War Illnesses

         Agency or contractor    Direct costs a             Work done
               BAHR Inc.                $11,796    Reviewed (1) processes and
                                                   technology used to produce
                                                estimates of U.S. forces
                                                potentially exposed and (2) draft
                                                reports
                                                          on Khamisiyah
         Central Intelligence                 b    Computer-modeling analysis
                Agency
          Chemical Biological                   Wood-surface evaporative modeling
           Defense Command,             140,000      and environmental data
        Aberdeen Proving Ground                          support efforts
    Defense Threat Reduction                  Computer-modeling analyses with
                Agency                  870,000      HPAC/SCIPUFF dispersion
                                                    and OMEGA weather models
         Institute for Defense                  Convened a panel of experts to
               Analyses                 149,429 review Khamisiyah pit modeling
                                                            analyses
          Lawrence Livermore                     Computer-modeling analyses with
          National Laboratory            60,000       ADPIC dispersion and
                                                      MATHEW weather models
          National Center for           308,000   Computer-modeling simulations
         Atmospheric Research                        using MM5 weather model
                                                Meteorological analysis to
                                                identify downwind hazard
    Naval Research Laboratory      1,090,000 assessment
                                                 with NOGAPS and COAMPS weather
                                                             models.
         Naval Surface Warfare                   Computer-modeling analyses with
                Center                  522,000      VLSTRACK dispersion and
                                                      COAMPS weather models
         Office of the Special                  Internal costs for producing case
        Assistant to the Deputy       7,980,000    narratives for Al Muthanna,
    Secretary of Defense for                   Khamisiyah, Muhammadiyat, and
          Gulf War Illnesses                                Ukhaydir
         Science Applications                 c    Computer-modeling analysis
    International Corporation
                                                Exposure assessment and
         U.S. Army Center for                   environmental modeling to
         Health Promotion and           731,000 determine

                                 Preventative Medicine

    U.S. troops' exposed to chemical releases from multiple incidents during
    the Gulf War

    U.S. Army Dugway Proving   1,861,950  Field trials and laboratory testing
                Ground                             using 122 mm chemical-
                                               simulant filled rockets to develop
                                                    source term data for modeling
         White Sands Missile          2,600    Missiles for testing at Dugway
                Range                                  Proving Ground
                Total           $13,726,775

    Sources: Agency and contractor responses provided to GAO on their modeling
    and analysis costs.

    aDirect costs for agencies includes funding for contracts provided by the
    Office of the Special Assistant to the Deputy Secretary of Defense for
    Gulf War Illnesses.

    bThe CIA denied our request for its costs for modeling chemical releases
    from Khamisiyah, as well as Al Muthanna, Muhammadiyat, and Ukhaydir.

    cSAIC did not respond to our requests for information.

    Indirect costs were much more difficult to obtain because the modeling
    efforts involved many people, and some were full-time while others were
    part-time. However, these estimates do not include, and DOD could not
    provide, an estimate of the considerable indirect costs involved for
    salaries of DOD and VA staff, contractors, facilities, travel, and
    equipment. In addition, the CIA would not provide us with the direct and
    indirect costs for modeling Gulf War plume and determinations of source
    term because, in its view, our request constituted oversight of an
    intelligence matter and is beyond our scope of authority. The CIA's
    contractor, SAIC, also would not respond to our request for cost
    information.

    DOD's and VA's Epidemiological Conclusions on CW Exposure and
    Hospitalization and Mortality Rates Cannot Be Adequately Supported

    DOD and VA each funded an epidemiological study on CW exposure- DOD's on
    hospitalization rates and VA's on mortality rates. From the
    hospitalization study conducted by DOD researchers and the mortality study
    conducted by VA researchers, DOD and VA each concluded that there was no
    significant difference in the rates of hospitalization and mortality
    between exposed and nonexposed troops. These conclusions, however, cannot
    be adequately supported by the available evidence. These studies contained
    two inherent weaknesses: (1) flawed criteria for classifying exposure,
    resulting in classification bias, and (2) an insensitive outcome measure,
    resulting in outcome bias. In addition, several other studies of Gulf War
    veterans, genetics, and animals found a strong association between
    exposure and illnesses.

    DOD and VA Used Flawed Criteria for Determining Troops' Exposure

    In the two epidemiological studies, DOD and VA researchers used DOD's 1997
    plume model for determining which troops were under the path of the
    plume-that is, were exposed-and which troops were not-that is, were not
    exposed. However, this classification is flawed, given their inappropriate
    criteria for inclusion and exclusion.

    In the hospitalization study, the DOD researchers included 349,291 Army
    troops "coded" as being in the Army on February 21, 1991. However, the
    researchers did not report a cutoff date for inclusion in the study-that
    is, they did not indicate whether these troops were in the Persian Gulf
    between January 17, 1991, and March 13, 1991, the period during which
    bombing and demolition took place. Although we requested this date, DOD
    researchers failed to provide it. Finally, the total number of 349,291
    troops is misleading because many troops left the service soon after
    returning from the Persian Gulf. Moreover, the researchers did not conduct
    any analyses to determine whether those who left were in the exposed or
    nonexposed group (including uncertain low-dose exposure or

    estimated subclinical exposure). Given all the methodological problems in
    this study, it is not possible to accurately determine the total number of
    the exposed and nonexposed groups.

    In the mortality study, the VA researchers included 621,902 Gulf War
    veterans who arrived in the Persian Gulf before March 1, 1991. Troops who
    left before January 17, 1991-the beginning of the bombing of Iraqi
    research, production, and storage facilities for CW agents-were included
    in the study. This group was not likely to have been exposed. Therefore,
    including them resulted in VA's overestimation of the nonexposed group.

    Troops who came after March 1, 1991-the period during which Khamisiyah
    demolition took place-were excluded from the VA study. The Defense
    Manpower Data Center (DMDC) identified 696,000 troops deployed to the
    Persian Gulf, but the mortality study included only the 621,902 troops
    deployed there before March 1, 1991. This decision excluded more than
    74,000 troops, approximately 11 percent of the total deployed. However,
    these troops were most likely to have been exposed. Therefore, excluding
    them resulted in underestimation of the size of the exposed group. In
    addition, 693 troops who were in the exposed group were excluded because
    identifying data, such as Social Security numbers, did not match the DMDC
    database. But VA researchers did not conduct follow-up analysis to
    determine whether those who were excluded differed from those who were
    included in ways that would affect the classification.

    DOD and VA Used an Insensitive Outcome Measure for Determining
    Hospitalization Rate

    Hospitalization rate-the outcome measure used in the hospitalization
    study-was insensitive because it failed to capture the chronic illnesses
    that Gulf War veterans commonly report but that typically do not lead to
    hospitalization. Studies that rely on this type of outcome as an end point
    are predetermined to overlook any association between exposure and
    illness.

    Based on DOD's 1997 plume model, DOD's hospitalization study compared the
    rates for Gulf War veterans who were exposed with the rates for those who
    were not exposed. This study included 349,291 active duty Army troops who
    were deployed to the Persian Gulf. However, DOD researchers did not
    determine the resulting bias in their analyses, because they did not
    account for those who left the service.

    The Institute of Medicine noted that the hospitalization study was limited
    to Army troops remaining on active duty and to events occurring in

    military hospitals. Conceivably, those who suffered from Gulf War-related
    symptoms might leave active duty voluntarily or might take a medical
    discharge. Hospitalization for this group would be reflected in VA or
    private sector databases but not in DOD databases. The health or other
    characteristics of active duty troops could differ from those of troops
    who left active duty and were treated in nonmilitary hospitals. Moreover,
    economic and other factors not related to health are likely to affect the
    use of nonmilitary hospitals and health care services.33

    This limiting of the study to troops remaining on active duty produced a
    type of selection bias known as the healthy warrior effect.34 It strongly
    biased the study toward finding no excess hospitalization among the active
    duty Army troops compared with those who left the service after the war.

    Some Studies Suggest an Association between CW Exposure and Gulf War
    Illnesses

    Gulf War Veterans Studies

    We found some studies that suggest an association between CW exposure and
    Gulf War illnesses. They are Gulf War veterans studies, genetics studies,
    and animal studies. Each of these studies, described below, has strengths
    and limitations.

    In a privately funded study, Haley and colleagues reported an association
    between a syndromic case definition of Gulf War illnesses, developed to
    model the ill veterans' symptomatic complaints, with exposure to CW
    agents.35 In this study, the authors developed questionnaires on symptoms
    and environmental exposure identified in pilot studies of ill Gulf War
    veterans, similar to epidemic investigations by the Centers for Disease
    Control and Prevention (CDC).36 These questionnaires were given to 249
    troops from a U.S. Navy Mobile Construction Battalion that participated in
    the Gulf War. Factor analysis of the data on symptoms was used to derive

    33Institute of Medicine, Gulf War Veterans: Measuring Health (Washington,
    D.C.: National Academy Press, 1999), p. 36.

    34R. W. Haley, "Point: Bias from the `Healthy-Warrior Effect' and Unequal
    Follow-Up in Three Government Studies of Health Effects of the Gulf War,"
    American Journal of Epidemiology 148 (1998): 315-38.

    35R. W. Haley and T. L. Kurt, "Self-Reported Exposure to Neurotoxic
    Chemical Combinations in the Gulf War," JAMA 277 (1997): 231-37.

    36See Michael B. Gregg, ed., Field Epidemiology, 2nd ed. (New York: Oxford
    University Press, 2002).

    a case definition identifying six syndrome factors.37 Three syndrome
    factor variants found to be the most significant were (1) impaired
    cognition, (2) confusion-ataxia, and (3) arthro-myo-neuropathy.

    Impaired cognition (syndrome 1) was associated with troops' having worn
    flea collars that contained chlorpyrifos.38 Confusion-ataxia (syndrome 2),
    the most severe clinically, was associated with three risk factors.39 The
    first was likely CW exposure; the second was the geographic location near
    the Saudi-Kuwaiti border around the fourth day of the air war, conducted
    January 18-23, 1991, when Czech chemical detection units detected sarin
    and mustard in ambient air near the Saudi-Kuwaiti border; and the third
    was side effects experienced after taking pyridostigmine. There was also a
    significant synergistic association between likely exposure to CW agents
    and the number of side effects from pyridostigmine.40 Arthro-myoneuropathy
    (syndrome 3) was associated with the amount of exposure to 95 percent DEET
    in ethanol insect repellent and with the number of side effects of
    pyridostigmine.41

    37R. W. Haley and others, "Is There a Gulf War Syndrome? Searching for
    Syndromes by Factor Analysis of Symptoms," JAMA 277 (1997): 215-22. The
    six syndrome factors were impaired cognition, confusion-ataxia,
    arthro-myo-neuropathy, phobia-apraxia, feveradenopathy, and
    weakness-incontinence.

    38Impaired cognition is characterized by problems with attention, memory,
    and reasoning, as well as insomnia, depression, daytime sleepiness, and
    headache. (Study results showed relative risk 8.2, 95 percent, CI
    2.9-23.5, p = 0.001.)

    39Confusion-ataxia is characterized by problems with thinking,
    disorientation, balance disturbances, vertigo, and impotence.

    40(1) CW exposure, relative risk 7.8, 95 percent, CI 2.3-25.9, p < 0.0001;
    (2) geographic location, relative risk 4.3, 95 percent, CI 1.9-10.0, p =
    0.004; (3) pyridostigmine side effects, dose-response trend up to relative
    risk 32.4, 95 percent, CI 7.8-135.0, p < 0.0001; (4) synergistic
    association, Rothman synergy statistic 5.3, 95 percent, CI 1.04-26.7, p <
    0.05. See Jonathan B. Tucker, "Evidence Iraq Used Chemical Weapons during
    the 1991 Persian Gulf War," The Nonproliferation Review 4:3 (Spring-Summer
    1997): 114-22. Center for Nonproliferation Studies, Monterey Institute of
    International Studies, http://cns.miis.edu/pubs (Apr. 28, 2004); and U.S.
    Department of Defense, Office of the Special Assistant for Gulf War
    Illnesses, Coalition Chemical Detections and Health of Coalition Troops in
    Detection Area (Washington, D.C.: Aug. 5, 1996).
    http://www.gulflink.osd.mil/czech_french/czfr_refs/n08en011/coalitn.html
    (Apr. 28, 2004).

    41Arthro-myo-neuropathy is characterized by joint and muscle pains, muscle
    fatigue, difficulty lifting, and paresthesias of the extremities. (Results
    showed for exposure, doseresponse effect to relative risk 7.8, 95 percent,
    CI 2.4-24.7, p < 0.0001; for side effects, doseresponse effect to relative
    risk 3.9, 95 percent, CI 1.3-12.1, p < 0.0001.)

    The inference that these risk-factor associations represent causal effects
    is supported by (1) the large, highly significant relative risks; (2) the
    doseresponse effects; and (3) the synergistic effect of the risk factor
    associations with the syndromic case definition. Risk factors found not to
    be significantly associated with the case definition include environmental
    pesticides, pesticides in uniforms, antibiotic or antimalarial
    prophylaxis, multiple immunizations, smoke from oil well fires, fumes from
    jet fuel, fumes from burning jet fuel in tents, petroleum in drinking
    water, depleted uranium munitions, smoking, alcohol use, and combat
    exposure.

    Another study of Gulf War veterans by Nisenbaum and colleagues, funded by
    CDC, examined the risk factors in 1,002 Air Force reservists.42 They
    found, first, that the case definition of Fukuda and colleagues of
    "multisymptom illness" was strongly associated with at least one of the
    three chronic symptom groups fatigue, mood/cognition, and musculoskeletal
    pain. And, next, they found that reported exposure to CW agents was most
    strongly associated with the "severe illness" case definition of Fukuda
    and colleagues and less strongly associated with their "mild-moderate
    illness" case definition.43

    Both case definitions were less strongly associated with the use of insect
    repellent (p = 0.006), the use of pyridostigmine (p = 0.01), and having an
    injury requiring medical attention (p = 0.03). But neither case definition
    was associated with smoke from oil well fires, coming under attack, seeing
    casualties, or having adverse health events in the family. The findings
    were attributed to the effects of stress but offered no empirical support
    for the explanation.

    In a study that VA funded, Proctor and colleagues compared the exposure
    histories of 186 Gulf War veterans from Fort Devens, Massachusetts, and 66
    from New Orleans, including 48 who deployed only to Germany. Collectively,
    the 252 veterans are known as the Massachusetts-New

    42R. Nisenbaum and others, "Deployment Stressors and a Chronic
    Multisymptom Illness among Gulf War Veterans," Journal of Nervous and
    Mental Disease 188 (2000): 259-66.

    43Association with "severe illness," adjusted OR 3.46, 95 percent, CI
    1.73-6.91, p < 0.0001; association with "mild-moderate illness," adjusted
    OR 2.25, 95 percent, CI 1.54-3.27, p < 0.0001. See K. Fukuda and others,
    "A Chronic Multisymptom Illness Affecting Air Force Veterans of the
    Persian Gulf War," JAMA 280 (1998): 981-88.

    Orleans cohort.44 The case definition was a set of eight body-system
    symptom scores (BSS, distributed from 0 to 4), each constructed by summing
    the 5-point frequency-of-occurrence scales (0 = occurs never, 4 = occurs
    almost every day) for three symptoms typical of a particular body system.
    The eight body systems were cardiac, dermatological, gastrointestinal,
    musculoskeletal, neurological, neuropsychological, psychological, and
    pulmonary. Post-traumatic stress disorder (PTSD) was diagnosed with the
    structural clinical interviews, Clinician Administered Posttraumatic
    Stress (CAPS) disorder scale, or a Mississippi Scale score of >89. The
    symptoms were obtained from the 52-item Expanded Health Symptom Checklist,
    the exposure measures from an environmental exposure questionnaire and an
    Expanded Combat Exposure Scale (CES) questionnaire. Multiple regression
    analysis-controlling for age, sex, education, study site, Expanded CES
    score, and PTSD status-was used to develop a risk-factor model for each
    BSS scale.

    Exposure to CW agents and debris from SCUD missiles was associated with
    four BSS scales; exposure to smoke from tent heaters, with three BSS
    scales; exposure to pesticides, vehicle exhaust, and burning human waste,
    with two BSS scales; the Expanded CES, with only one BSS scale; and
    exposure to pyridostigmine bromide (antinerve gas pills) and smoke from
    oil well fires, with no BSS scale. Controlling for depression scores and
    excluding veterans diagnosed with PTSD did not substantially affect the
    associations.

    Three additional studies conducted with VA and DOD funding extended the
    risk-factor research for the Massachusetts-New Orleans cohort. The
    association of self-reported CW agent (nerve agent) exposure was tested
    with different formulations of the case definition. White and colleagues
    used psychological and neuropsychological tests to define illness. They
    found that exposure to CW agents was associated with abnormal measures of
    mood, memory, and attention or executive function.45 Associations remained
    significant after controlling for age, sex, race, years of education,
    repeated grade in school, head injury, medication use, diagnosis of
    current

    44S. P. Proctor and others, "Health Status of Persian Gulf War Veterans:
    Self-Reported Symptoms, Environmental Exposures, and the Effect of
    Stress," International Journal of Epidemiology 27 (1998): 1000-10.

    45R. F. White and others, "Neuropsychological Function in Gulf War
    Veterans: Relationships to Self-Reported Toxicant Exposures," American
    Journal of Industrial Medicine 40 (2001): 42-54.

    PTSD (by CAPS), diagnosis of current depression (by structural clinical
    interviews), active duty versus Reserve or Guard status, seeking
    disability rating, and Vietnam service.

    Lindem and colleagues developed multiple regression models for
    neuropsychological test measures as case definitions of Gulf War
    illnesses.46 Chemical warfare agent exposure was found to be associated
    with attention and executive function (continuous performance test),
    delayed verbal recall (California Verbal Learning Test and Visual
    Reproduction Test), and confusion and fatigue (Profile of Mood States).
    These associations remained significant when controlling for age,
    education, and PTSD diagnosis (by CAPS).

    Wolfe and colleagues, studying 945 troops from the Massachusetts-New
    Orleans cohort, found that the CDC case definition of multisymptom illness
    was most strongly associated with having smelled a chemical odor, having
    taken up to 21 antinerve gas pills, or having experienced up to 10 formal
    alerts for CW agent attack.47

    Kang and colleagues conducted a random sample mail survey that VA funded.
    Obtaining responses from 11,441 Gulf War veterans and 9,476 nondeployed
    Gulf War era veterans, they developed a case definition by factor analysis
    of symptoms measured by their questionnaire.48 The first three syndrome
    factors closely resembled those that Haley and others derived (noted
    earlier). Finding that syndrome 2 was unique to the sample that had been
    deployed in the Gulf War (found in the deployed, but not the nondeployed,
    sample) and that the component symptoms were neurological in character,
    the researchers termed their syndrome 2 a possible unique Gulf War
    neurological syndrome. Four symptoms- blurred vision, loss of balance or
    dizziness, tremor or shaking, and speech difficulties-were associated with
    syndrome 2 only in the deployed sample. Consequently, Kang and colleagues
    established their case

    46K. Lindem and others, "Neuropsychological Performance in Gulf War Era
    Veterans: Traumatic Stress Symptomatology and Exposure to
    Chemical-Biological Warfare Agents, Journal of Psychopathology and
    Behavioral Assessment 25:2 (2003): 105-19.

    47Chemical odor, OR = 6.2, 95 percent, CI 3.9-9.9; antinerve gas pills, OR
    = 3.7, 95 percent, CI 2.4-5.6; formal alerts for CW attack, OR = 2.7, 95
    percent, CI 2.0-3.7. See J. Wolfe and others, "Risk Factors for
    Multisymptom Illness in U.S. Army Veterans of the Gulf War," Journal of
    Occupational and Environmental Medicine 44:3 (2002): 271-81.

    48H. K. Kang and others, "Evidence for a Deployment-Related Gulf War
    Syndrome by Factor Analysis," Archives of Environmental Health 57:1
    (2002): 61-68.

    definition as having all four of these symptoms. In the deployed sample,
    277 met the case definition and 6,730 who had none of the four symptoms
    constituted the control group. Of a large number of risk factors analyzed,
    only nine were associated with the case definition, with an odds ratio
    greater than 3.0. Of these, perceived exposure to nerve agent had the
    strongest association (odds ratio 15.1, 95 percent, CI 11.5-19.9, p <
    0.000001). This finding-a neurological syndrome appearing as the second
    factor in a factor analysis and being the most strongly associated risk
    factor, 15 times more common in ill veterans meeting the case definition
    than in controls-closely parallels the findings of Haley and colleagues.
    The finding received little notice, however, because the VA-funded mail
    survey did not (1) provide the odds ratio values in the table reporting
    the risk factor analysis results and (2) describe the finding in the text
    or abstract of the paper. When we noticed the finding, we manually
    calculated the odds ratios from the raw data in the table.

    Smith and colleagues showed that hospitalization rates for several ICD-9
    diagnoses were higher in veterans categorized in the Khamisiyah 2000 plume
    than in those not in the plume, and the association for cardiac
    arrhythmias was statistically significant. However, this study suffers
    from the same deficiencies as the earlier study that we cited: use,
    inappropriately, of hospitalization outcome measures rather than measures
    of Gulf War illness, which usually do not result in hospitalization, and
    use of plume modeling based on flawed data.49

    The 2002 Kang and Bullman study has not been published in a peerreviewed
    journal and therefore should not have been included in a review of the
    scientific epidemiologic literature. The DOD studies were invalid for two
    reasons: (1) Hospitalization and mortality were inappropriate outcomes
    because they do not measure Gulf War illnesses, which often do not lead to
    hospitalization, and (2) The DOD studies, no matter how powerful their
    techniques, could not control for the selection bias that resulted from
    the disproportionate early discharge of the ill Gulf War veterans soon
    after the Gulf War. Including only DOD hospital records of service members
    remaining on active duty resulted in the exclusion of veterans who left
    service for poor health. No amount of sophisticated

    49T. C. Smith and others, "Gulf War Veterans and Iraqi Nerve Agents at
    Khamisiyah: Postwar Hospitalization Data Revisited," American Journal of
    Epidemiology 158 (2003): 457-67.

    Genetics Studies

    techniques can correct for this selection bias toward finding no

    50

    difference.

    In one genetics study, Haley and colleagues found an association between
    the case definition of Gulf War illnesses in U.S. Gulf War veterans and
    low blood levels of the Q-type isoenzyme of the paraoxonase/arylesterase
    enzyme group (PON).51 The PON group of enzymes is a potentially important
    predisposing factor in Gulf War illnesses because one of its major
    functions in normal body physiology is to protect the nervous system from
    organophosphate chemical toxins, such as pesticides and nerve agents. This
    finding was remarkable because the only function of Q type of the PON
    enzyme group is to protect the nervous system from nerve agents sarin,
    soman, tabun, and VX. The R-type isoenzyme has as its main function
    protection from organophosphate pesticides, such as diazinon, malathion,
    and parathion. Thus, an association between Gulf War illnesses and blood
    levels of only the Q-type isoenzyme of PON points specifically to nerve
    agent exposure. In addition, the total PON level-that is, the sum of the Q
    and R isoenzyme levels-was not associated with the illnesses. And the
    genotype (QQ, QR, or RR) was only marginally associated with them, as
    expected, because the level of the Q-type isoenzyme is a more important
    determinant of susceptibility to nerve agents than the genotype.

    In another genetics study, Mackness and colleagues reported lower blood
    levels of total PON in ill British Gulf War veterans than in civilian
    controls in a previously published study; however, they did not measure
    the blood levels of the Q and R isoenzymes of PON, needed for a definitive
    study of Haley's hypothesis.52 This finding could indicate that ill
    British Gulf War veterans represented a mixture of some with low Q-type
    PON and others with low R-type PON. In some veterans, the illness would be
    associated with exposure to nerve agents; in others, with exposure to
    pesticides. Alternatively, the difference in total PON levels may have
    resulted from differences in the assays or in the veterans, since (1) the
    enzyme assays in

    50H. K. Kang and T. A. Bullman, Mortality among U.S. Gulf War Veterans Who
    Were Potentially Exposed to Nerve Gas at Khamisiyah, Iraq (Washington, DC:
    Department of Veterans Affairs, May 2002).

    51R. W. Haley and others, "Association of Low PON1 Type Q (Type A)
    Arylesterase Activity with Neurologic Symptom Complexes in Gulf War
    Veterans," Toxicology and Applied Pharmacology 157 (1999): 227-33.

    52B. Mackness and others, "Low Paraoxonase in Persian Gulf War Veterans
    Self-Reporting Gulf War Syndrome," Biochemical and Biophysical Research
    Communications 276 (2000): 729-33.

    the controls were performed years before those for the ill veterans and
    (2) the controls were civilians studied in an entirely different setting.

    In yet a third genetics study, Hotopf and colleagues reported results of
    tests for total PON levels in blood samples-obtained in a study by Unwin
    and colleagues-for four groups of British troops: (1) ill veterans of the
    Gulf War, (2) well veterans of the Gulf War, (3) ill nondeployed veterans
    of the Gulf War era, and (4) ill veterans of the Bosnian conflict.53 The
    case definition of illness was a score below 72.2 on the SF-36 Physical
    Status questionnaire. Again, the researchers did not measure the levels of
    the Q and R isoenzymes of PON, making the findings difficult to interpret.
    The researchers found a low mean level of total PON in both ill and well
    groups deployed to the Gulf War and higher levels in the Gulf War era and
    ill Bosnian groups.

    The depressing of the total PON level, the researchers suggested, might be
    the result of some deployment-related exposures. However, instead of
    looking at exposure to CW agents, the researchers investigated the
    possible effect of multiple immunizations on total PON levels and found no
    evidence for it. An alternative explanation is that total PON level in
    both ill and well deployed veterans was the result of misclassification of
    veterans by the case definition. A score of 72.2 on the SF-36 scale is not
    a very low score, particularly in ill Gulf War veterans, and it is a
    nonspecific measure of illness, given that a low score indicates illness
    from any cause.54 Consequently, many veterans ill from causes unrelated to
    the war would be misclassified as cases of Gulf War illness and,
    conversely, many ill from the war but with less disability would be
    misclassified as controls. This conclusion is supported by a
    nonsignificant trend showing that ill veterans who had been deployed to
    the Gulf War had a lower median total PON level than well veterans who had
    also been deployed to the Gulf War.

    The many flaws of design and methodology in both British studies of PON
    levels do not contribute to an understanding of the PON hypothesis and
    leave the finding of Haley and colleagues in need of better replication.

    53See Matthew Hotopf and others, "Paraoxonase in Persian Gulf War
    Veterans," Journal of Occupational and Environmental Medicine 45 (2003):
    668-75, and C. Unwin and others, "Health of UK Servicemen Who Served in
    the Persian Gulf War," Lancet 353 (1999): 169-78.

    54R. W. Haley and others, "Severely Reduced Functional Status in Veterans
    Fitting a Case Definition of Gulf War Syndrome," American Journal of
    Public Health 92 (2002): 46-47.

    Animal Studies

    A series of laboratory studies with animals have established the
    biological plausibility that brain cell damage results from low-level
    exposure to sarin. Husain and colleagues demonstrated in two studies at
    the Division of Pharmacology and Toxicology at the Defense Research and
    Development Establishment in Gwalior, India, that repetitive
    administration of low-dose sarin (approximately 0.25 LD50) daily for 10
    days caused delayed onset damage to neurons in the spinal cords and brains
    of mice exposed by inhalation and of hens exposed by subcutaneous
    injection.55

    Privately funded studies by Abou-Donia and colleagues demonstrated that
    combinations of organophosphates and similar cholinesterase-inhibiting
    chemicals in hens produce greater neurotoxic effect on brain and nerve
    tissue than any of the agents alone.56 Abou-Donia's subsequent work,
    funded by DOD, extended the findings to synergistic combinations involving
    sarin at moderate concentrations (0.5 LD50).57 A similar study by Husain
    and Somani, also funded by DOD, on the delayed brain effects of low-dose
    sarin (0.05 LD50) in combination with pyridostigmine and exercise,
    confirmed these findings. In particular, it demonstrated that the neuronal
    damage from very low doses of sarin affected primarily the basal ganglia
    region of the brain (striatum).58

    A study by Henderson and colleagues, with DOD funding, found that repeated
    inhalation exposure to low-level sarin at subsymptomatic doses

    55K. Husain and others, "Delayed Neurotoxic Effect of Sarin in Mice after
    Repeated Inhalation Exposure," Journal of Applied Toxicology 13 (1993):
    143-45, and "A Comparative Study of Delayed Neurotoxicity in Hens
    Following Repeated Administration of Organophosphorus Compounds," Indian
    Journal of Physiology and Pharmacology 39 (1995): 47-50.

    56Mohamed B. Abou-Donia and others, "Neurotoxicity Resulting from
    Coexposure to Pyridostigmine Bromide, DEET, and Permethrin," Journal of
    Toxicology and Environmental Health 48 (1996): 35-56, and "Increased
    Neurotoxicity Following Concurrent Exposure to Pyridostigmine Bromide,
    DEET, and Chlorpyrifos," Fundamentals of Applied Toxicology 34 (1996):
    201-22.

    57Mohamed B. Abou-Donia and others, "Combined Exposure to Sarin and
    Pyridostigmine Bromide Increased Levels of Rat Urinary 3-Nitrotyrosine and
    8-Hydroxy-2'-Deoxyguanosine, Biomarkers of Oxidative Stress," Toxicology
    Letters 123 (2001): 51-58; "Disruption of the Blood-Brain Barrier and
    Neuronal Cell Death in Cingulate Cortex, Dentate Gyrus, Thalamus, and
    Hypothalamus in a Rat Model of Gulf-War Syndrome," Neurobiology of Disease
    10 (2002): 306-26; and "Sarin: Health Effects, Metabolism, and Methods of
    Analysis," Food and Chemical Toxicology 40 (2002): 1327-33.

    58K. Husain and S. Somani, "Delayed Toxic Effects of Nerve Gas Sarin and
    Pyridostigmine under Physical Stress in Mice," Journal of Burns and
    Surgical Wound Care 2 (2003): 2-19.

    (0.1 LCt50) for 5 or 10 days, with or without heat stress, produced no
    immediate effects.59 But at 30 days after exposure to sarin, damage was
    produced to cholinergic receptors in several brain regions, including the
    basal ganglia. In the same study, Henderson and colleagues identified
    evidence of an autonomic nervous system injury affecting the function of
    T-cells in the immune system as well.60 In addition, chronic abnormalities
    of neuronal metabolism in the basal ganglia have been implicated in ill
    Gulf War veterans by several investigators through the use of magnetic

    61

    resonance spectroscopy.

    Two recent laboratory studies at the U.S. Army Medical Research Institute
    of Chemical Defense, Aberdeen Proving Ground, support the animal studies.
    Scremin and colleagues demonstrated that moderate doses of sarin (0.5
    LD50) in combination with pyridostigmine bromide produced prolonged
    elevations in rats' cerebral blood flow but that neither agent alone had a
    prolonged effect on cerebral blood flow.62 A companion study, by Roberson
    and colleagues, demonstrated that repeated administration of sarin to
    guinea pigs in doses of 0.2 or 0.4 LD50 produced no immediate ill effects
    on behavior, weight, body temperature, flinch threshold, or EEG brain wave
    activity. But at 100 days postdosing, abnormal brain function was found,
    indicating neurochemical or pathological brain cell changes

    63

    that affect behavior.

    59R. F. Henderson and others, "Response of F344 Rats to Inhalation of
    Subclinical Levels of Sarin: Exploring Potential Causes of Gulf War
    Illness," Journal of Toxicology and Industrial Health 17 (2001): 294-97
    and 18:1 (2002): 48.

    60See Henderson and others, "Response of Rats to Low Levels of Sarin," and
    "Subclinical Doses of the Nerve Gas Sarin Impair T Cell Responses through
    the Autonomic Nervous System," Journal of Toxicology and Applied
    Pharmacology 184 (2002): 82-87.

    61See R. W. Haley and others, "Brain Abnormalities in Gulf War Syndrome:
    Evaluation by 1H Magnetic Resonance Spectroscopy," Radiology 215 (2000):
    807-17, and "Effect of Basal Ganglia Injury on Central Dopamine Activity
    in Gulf War Syndrome: Correlation of Proton Magnetic Resonance
    Spectroscopy and Plasma Homovanillic Acid," Archives of Neurology 57
    (2000): 1280-85, as well as D. J. Meyerhoff and others, "Reduced
    N-Acetylaspartate in the Right Basal Ganglia of Ill Gulf War Veterans by
    Magnetic Resonance Spectroscopy," Proceedings of the International Society
    of Magnetic Resonance Medicine 9 (2001): 994.

    62O. U. Scremin and others, "Effects of Chronic Exposure to Low Levels of
    Cholinesterase Inhibitors on Cerebral Blood Flow," paper for the Society
    for Neuroscience Meeting, Orlando, Florida, 2002.

    63Melinda Roberson and others, "Depression of Cholinesterase Activity by
    Low-Dose Sarin Exposure May Lead to Persistent Changes That Influence
    Behavior," Society for Neuroscience, Washington, D.C., Program no. 205.3
    (Abstract, 2002).

    Conclusions

    In evaluating the weaknesses of the plume models, we conclude that the
    results from the CIA and DOD modeling can never be definitive. Plume
    models can allow only estimates of what happens when CW agents are
    released in the environment. Such estimates are based on mathematical
    equations, which are used to predict an actual event-in this case, the
    direction and extent of the plume. However, in order to predict precisely
    what happens, one needs to have accurate data on source term and
    meteorological conditions. DOD had neither of these.

    Given the unreliability of the input data, the lack of troop location
    data, and the divergent results of modeling, DOD's analyses cannot
    adequately determine the extent of U.S. troops' exposure. In particular,
    the models selected were not fully developed for projecting long-range
    environmental fallout, and the assumptions used to provide the source term
    data were flawed. Even when models used the same source term data, their
    results diverged. In addition, the models did not include many potential
    exposure events and some key materials-for example, binary chemical
    weapons, mustard agent combustion by-products, and CW agent precursor
    materials. It is likely that if models were more fully developed, and if
    more credible data for source term and meteorological conditions were
    included in them, particularly with respect to plume height as well as
    level and duration of exposure, the hazard area would be much larger and
    most likely would cover most of the areas where U.S. troops and Coalition
    forces were deployed. However, given the lack of verifiable data for
    analysis, it is unlikely that any further modeling efforts would be more
    accurate or helpful.

    The results of DOD's modeling efforts were, nonetheless, used in
    epidemiological studies to determine the troops' CW exposure
    classification-exposed versus nonexposed. As we noted in 1997, to
    ascertain the causes of veterans' illnesses, it is imperative that
    investigators have valid and reliable data on exposure, especially for
    lowlevel or intermittent exposures to CW agents.64 To the extent that
    veterans are misclassified as to exposure, relationships will be obscured
    and conclusions misleading. In addition, DOD combined the results of
    individual models that showed smaller plume size and ignored the results

    64U.S. General Accounting Office, Gulf War Illnesses: Improved Monitoring
    of Clinical Progress and Reexamination of Research Emphasis Are Needed,
    GAO/NSIAD-97-163 (Washington, D.C.: June 23, 1997).

    of the LLNL model, which showed much larger plume size. Given the
    uncertainties in source term data and divergences in model results, DOD
    cannot determine-with any degree of certainty-the size and path of the
    plumes or who was or who was not exposed.

    Recommendations for Executive Action

    Agency Comments and Our Evaluation

    We recommend that the Secretary of Defense and the Secretary of Veterans
    Affairs not use the plume-modeling data for future epidemiological studies
    of the 1991 Gulf War, since VA and DOD cannot know from the flawed plume
    modeling who was and who was not exposed.

    We recommend that the Secretary of Defense require no further plume
    modeling of Khamisiyah and the other sites bombed during the 1991 Gulf War
    in order to determine troops' exposure. Given the uncertainties in the
    source term and meteorological data, additional modeling of the various
    sites bombed would likely result in additional cost while still not
    providing DOD with any definitive data on who was or was not exposed.

    We obtained comments on a draft of this report from VA, DOD, and the CIA.
    VA concurred with our first recommendation (see appendix V). Nevertheless,
    VA stated that it has already completed three studies that incorporated
    the DOD plume model as part of the parameters for the research and has
    submitted these studies to scientific journals for publication. In
    addition, VA is currently collaborating with other research groups that
    may have used the DOD plume model. These studies are under way and will be
    completed as planned. Given our assessment, it is important that VA inform
    the researchers to include appropriate caveats, indicating the limitation
    of the conclusions based on flawed modeling data.

    DOD did not concur with our first recommendation, indicating that the "GAO
    recommendation apparently represents a blanket prohibition against plume
    modeling in the future, where the limitations of the 1991 Gulf War may not
    apply" (see page 77). The intent of our recommendation was directed only
    at epidemiological studies involving the DOD and CIA plume modeling data
    from the 1991 Gulf War and was not a blanket prohibition of plume modeling
    in the future (see appendix VI). We have clarified the recommendation
    along these lines.

    The CIA did not concur with the report, indicating that it could not
    complete a review in the time allotted. The CIA indicated that a

    comprehensive review would require 3 to 4 weeks. Nevertheless, from its
    preliminary review of our report, the CIA identified several statements
    that it considered inaccurate, such as those about source term data. The
    CIA contended that the agent source term is complete and accurate to a
    known certainty. Since our initiation of this inquiry in late 2002, we
    have met with the CIA on a number of occasions, most recently on April 7,
    2004, to identify the methodologies pursued in establishing source term
    parameters used in the modeling. At the suggestion of the CIA, we met with
    UNMOVIC officials to determine what UNSCOM inspections disclosed and the
    methodologies used in determining source term data.

    Our point-by-point evaluation of the detailed comments provided by DOD are
    presented in appendix VI.

    As we agreed with your offices, unless you publicly announce the contents
    of this report earlier, we plan no further distribution until 30 days from
    its issue date. We will then send copies of the report to other interested
    congressional members and committees. In addition, the report will be
    available at no charge on GAO's Web site at http://www.gao.gov.

    If you or your staff have any questions about this report or would like
    additional information, please contact me at (202) 512-6412 or Sushil
    Sharma, Ph.D., Dr.PH., at (202) 512-3460. We can also be reached by e-mail
    at rhodesk@gao.gov and sharmas@gao.gov.

    Individuals who made key contributions to this report were Venkareddy
    Chennareddy, Susan Conlon, Neil Doherty, Jason Fong, Penny Pickett, Laurel
    Rabin, Katherine Raheb, and Joan Vogel. James J. Tuite III, a GAO
    consultant and recognized expert on Gulf War issues, provided technical
    expertise.

    Keith Rhodes, Chief Technologist Center for Technology and Engineering
    Applied Research and Methods

    Appendix I: DOD's Chronology of Khamisiyah Modeling Events

                                       Date Event

    1995

    June	DOD formed the Persian Gulf Illnesses Investigation Team; by October,
    it had identified some of the U.S. forces that had occupied the area
    around Khamisiyah during the Gulf War, including the 37th Engineer
    Battalion

    Aug. President Bill Clinton created the Presidential Advisory Committee on
    Gulf War Veterans' Illnesses

    1996

    Spring 	The Presidential Advisory Committee on Gulf War Veterans'
    Illnesses directed the CIA to model chemical agent release from Bunker 73

                            May UNSCOM inspected Khamisiyah

    June 	DOD confirmed publicly that "US soldiers from the 37th Engineer
    Battalion destroyed ammunition bunkers [at Khamisiyah] in early March
    1991.... It now appears that one of these destroyed bunkers contained
    chemical weapons"

    July The CIA briefed the Presidential Advisory Committee on Bunker 73
    modeling results

    Oct. 	The CIA requested LLNL to perform atmospheric dispersion
    calculations, using a hypothetical release scenario; the Deputy Secretary
    of Defense sent a memorandum to 21,000 veterans who had been identified as
    being within 50 km of Khamisiyah

    Nov. 	The Secretary of Defense established the Office of the Special
    Assistant for Gulf War Illnesses (OSAGWI) to focus ongoing DOD
    investigations and expand the investigation into Gulf War veterans'
    complaints of undiagnosed illnesses

    Dec. 	IDA released its interim report, critical of the model the CIA used;
    it recommended rocket demolition testing to determine how rockets behaved
    without high explosives and an ensemble approach with prognostic models

    1997

    Jan. 	The Deputy Secretary of Defense sent letters with a survey to
    veterans, saying that chemical weapons had been present at Khamisiyah when
    the demolitions occurred and urging them to call the Persian Gulf Incident
    Hotline with any additional information they had about Khamisiyah

    Jan.-Feb. 	The Special Assistant agreed to remodel Khamisiyah, as well as
    Al Muthanna, Muhammadiyat, and Ukhaydir, following entreaties by the
    Presidential Advisory Committee on Gulf War Veterans' Illnesses and IDA's
    recommendations

    May 	DOD and the CIA conducted open-field demolition tests on 122 mm
    rockets similar to those destroyed in the Khamisiyah pit at Dugway Proving
    Ground, Utah, to determine how CW agents in Iraq's rockets might have been
    released

    May (to June The Department of the Army and OSAGWI hosted G3/S3
    conferences to elicit more correct information on unit 1998) locations
    during the war

                   June-July CW agent release was modeled at the pit

    July	IDA released its final report, "Report of the Panel Reviewing
    Analysis of the Khamisiyah Pit Release of Nerve Agent, March 1991"; DOD
    and the CIA jointly announced the results of Khamisiyah dispersion
    modeling. Given the unit locations available then, the modeling indicated
    a hazard area where troops may have been exposed to low levels of nerve
    agent. DOD sent written notices to 98,910 veterans in the potential hazard
    area and approximately 10,000 notices to those who had received the Deputy
    Secretary of Defense's letter and survey but were not in the potential
    hazard area

    Dec. 	An independent scientific panel (Anthes and others) reviewed and
    commented on the methodology used to complete the Khamisiyah modeling,
    making recommendations for improvements in future modelinga

               Appendix I: DOD's Chronology of Khamisiyah Modeling Events

    Date Event

    1998: Jan.	President Clinton created the Presidential Special Oversight
    Board for the Department of Defense Investigations of Gulf War Chemical
    and Biological Incidents to provide recommendations, based on its review
    of DOD investigations into possible detection of, and exposures to,
    chemical or biological weapons agents, as well as environmental and other
    factors that might have contributed to Gulf War illnesses

    2000

    Jan. 	DOD completed efforts to remodel the Khamisiyah release using
    updated meteorological and dispersion models, with revised source terms
    from the CIA and with a better understanding of where U.S. forces had
    been. As a result, DOD's estimate of the number possibly exposed increased
    by about 2,000; almost 35,000 troops who had previously been notified of
    possible exposure were no longer in the possible hazard area, whereas
    about 37,000 newly identified troops probably were

    Mar. 	The scientific review committee completed its review of the revised
    methodology, commenting that "the methodologies are sound" and "the
    results ... very likely overestimate the dosages actually received by
    personnel"

    2002: Apr. DOD published its final Khamisiyah report, with complete
    technical report documenting methodologies

    Source: Department of Defense, Office of the Assistant Secretary of
    Defense for Health Affairs, Deployment Health Support Directorate.

    a Richard A. Anthes and others, "Comments by Review Panel on Khamisiyah
    Modeling Report and Presentations on November 4-5, 1997," report for the
    Directorate for Deployment Health Support of the Special Assistant to the
    Under Secretary of Defense (Personnel and Readiness) for Gulf War
    Illnesses, Medical Readiness, and Military Deployments, Fairfax, Virginia,
    December 11, 1997.

                             Appendix II: Power-Law Formula

    A 1969 Sandia National Laboratories empirical study established a powerlaw
    formula for calculating plume heights attributable to high-explosive
    detonations. The power-law formula was derived from data on 23 test shots,
    ranging from 140 lbs. to 2,242 lbs. of high explosives at DOE's Nevada
    Test Site (the National Exercise, Test, and Training Center), and it
    provides a cloud-top height at 2 minutes after detonation. Most of the
    shots were detonated during near-neutral conditions, where the clouds
    continued to rise after 2 minutes; data for 5 minutes after detonation on
    some shots show tops rising to nearly double the 2-minute values. The
    2minute values better represent the final cloud-top heights during stable
    conditions.

    This formula is represented as

    h = 76 (w1/4)

    where

                           h = height of plume in meters and

                           w = weight of explosives in pounds

    According to this formula, an MK-84 or GBU-24 bomb (942.6 lbs. of high
    explosives) would generate a plume of 421 meters:

    h = 76 (942.6 pounds of high explosives)1/4

    h = 76 (5.541)

    h  o  421 meters

                         Appendix III: DOD's Model Divergences

    Even among the models selected for use by the DOD panel, widely divergent
    directional outcomes were observed. For example, in figure 13, the
    differences among various models for hazard areas during the first 2 days
    of the modeling period for Khamisiyah can be seen.

      Khamisiyah Pit Demolition - March 10, 1991 Modeled Exposure (Deposition and
               Degradation) Modeled Exposure (Deposition and Degradation)

                                           N

                      VLSTRACK/COAMPS VLSTRACK/COAMPS HPAC/COAMPS

    HPAC/COAMPS

    N

                                        HPAC/MM5

    Angle approximately equal Angle approximately equal to 40-45 degrees to 80
    degrees

    Each dot represents a troop unit's location or part of a unit's location.
    Each unit can range in size from a company to a batallion.

    Source: Naval Surface Warfare Center.

    In the March 10, 1991, section of the figure, an approximately 40 to 45
    degree divergence between the HPAC/OMEGA and the HPAC/COAMPS models can be
    seen; in the March 11, 1991, section, an approximately 80 degree
    divergence can be seen.

    The uncertainty attributed to this divergence is not limited to the
    Khamisiyah modeling. According to a modeling analyst involved with the
    modeling of Al Muthanna, the COAMPS and OMEGA weather models showed the
    plume going in different directions, at a difference of 110 to 120
    degrees. According to the analyst, COAMPS showed the plume going north
    northwest, while OMEGA showed it going south. Similar divergence

                         Appendix III: DOD's Model Divergences

    among model projections was also observed in the modeling of Muhammadiyat,
    as shown in figure 14.

                             Source: Department of Defense.

    Appendix IV: Divergence and Wind Field Models

    In figure 15, LLNL projections for divergence of wind field vectors 6.0 m
    above terrain are based on observational data the Meteorological Data
    Interpolation Code (MEDIC) model processed.

    Appendix IV: Divergence and Wind Field Models

    Source: Lawrence Livermore National Laboratory.

    Page 70 GAO-04-159 Gulf War Illnesses

    Appendix IV: Divergence and Wind Field Models

    Figure 16 shows the wind field vector model, based on European Centre for
    Medium-Range Weather Forecast (ECMWF) projections and processed by the
    MEDIC model.

    Source: Lawrence Livermore National Laboratory.

    Page 71 GAO-04-159 Gulf War Illnesses

                     Appendix IV: Divergence and Wind Field Models

    The wind field vector model in figure 17 is based on COAMPS simulations at
    the U.S. Naval Research Laboratories.

                    Source: Lawrence Livermore National Laboratory.

                         Page 73 GAO-04-159 Gulf War Illnesses

    Appendix VI: Comments from the Department of Defense

    Note: GAO comments supplementing those in the report text appear at the
    end of this appendix.

                  Appendix VI: Comments from the Department of Defense

                                     See comment 1.

                  Appendix VI: Comments from the Department of Defense

                                     See comment 2.

                                     Now on p. 60.

                                     See comment 3.

                  Appendix VI: Comments from the Department of Defense

    See comment 4.

    See comment 5. See comment 6. See comment 7.

    See comment 8.

    See comment 9.

    See comment 10.

    See comment 11.

    Now on pp. 50-55.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 1.
    See comment 12.

    Now on p. 2.
    See comment 13.

    Now on p. 2.
    See comment 14,

    Now on p. 2.
    See comment 15.

    Now on p. 3.
    See comment 16.

    Now on p. 6.
    See comment 17.

    Now on p. 5.
    See comment 18.

                  Appendix VI: Comments from the Department of Defense

    See comment 19.

    Now on p. 10. See comment 20.

    Now on p. 11. See comment 21.

    Now on p. 11. See comment 22.

    Now on p. 12. See comment 23.

    Now on p. 12. See comment 24.

    Now on pp. 13-14. See comment 25.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 13. See comment 26.

    Now on p. 14. See comment 27.

    Now on p. 14. See comment 28.

    Now on p. 14. See comment 29.

    Now on p. 15. See comment 30.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 16. See comment 31.

    Now on p. 18. See comment 32.

    Now on p. 18. See comment 33.

    Now on p. 19. See comment 34.

    Now on p. 19. See comment 35.

    Now on p.19. See comment 36.

    Now on p. 20 See comment 37.

    Now on p. 20. See comment 38.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 20. See comment 39.

    Now on p. 21. See comment 40.

    Now on p. 23. See comment 41.

    Now on p. 25. See comment 42.

    Now on p. 27. See comment 43.

    Now on p. 27. See comment 44.

                  Appendix VI: Comments from the Department of Defense

    Now on pp. 27 and 29. See comment 45.

    Now on p. 28. See comment 46.

    Now on p. 29. See comment 47.

    Now on p. 30. See comment 48.

    Now on pp. 30-34. See comment 49.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 31-32. See comment 50.

    Now on p. 32. See comment 51.

    Now on p. 34. See comment 52.

    Now on p. 34. See comment 53.

    Now on p. 34. See comment 54.

                  Appendix VI: Comments from the Department of Defense

                                   Now on pp. 35-37.

                                    See comment 55.

    Now on p. 37.

                  Appendix VI: Comments from the Department of Defense

    See comment 56.

    Now on p. 38. See comment 57.

    Now on pp. 41 and 43. See comment 58.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 44. See comment 59.

    Now on p. 44. See comment 60.

    Now on p. 45. See comment 61.

    Now on p. 45. See comment 62.

    Now on pp. 49-60. See comment 63.

                  Appendix VI: Comments from the Department of Defense

                                   Now on pp. 51-60.

                                    See comment 64.

                  Appendix VI: Comments from the Department of Defense

    Now on pp. 59-60. See comment 65.

    Now on pp. 50-51. See comment 66.

                  Appendix VI: Comments from the Department of Defense

    Now on pp. 49-50. See comment 67.

    Now on pp. 70-72. See comment 68.

                  Appendix VI: Comments from the Department of Defense

    Now on p. 72. See comment 68.

                  Appendix VI: Comments from the Department of Defense

                                      GAO Comments

    1. 	The use of the phrase "flawed plume modeling" in the report refers to
    the use of DOD models that were not fully developed for analyzing
    long-range dispersion of CW agents as an environmental hazard. In
    addition, the uncertain source term data used resulted in a flawed
    modeling outcome. Meteorological and dispersion modeling, as predictive
    and diagnostic tools, can have significant value in cases where detailed
    meteorological data are unavailable and in providing warning for potential
    environmental hazards, assuming that the necessary input data supplied to
    the model are accurate. DOD now asserts that it has made significant
    improvements in its models; however, we have not evaluated DOD's
    assertion, since it was beyond the scope of this study.

    2. 	We revised the recommendation to state: "We recommend that the
    Secretary of Defense and the Secretary of VA not use the plume modeling
    data as a basis for future epidemiological studies of Gulf War Illnesses
    in Iraq, since DOD and VA cannot know who was or who was not exposed."

    DOD correctly states that the necessary input data (i.e., source term and
    meteorological data) were not available. However, the models that DOD used
    were not fully developed for long-range dispersion of CW agents as an
    environmental hazard. Consequently, the modeling results were not fully
    reliable for determining which troops were exposed or were not exposed.

    The report did not intend to suggest that modeling, in general, is a
    flawed approach for predicting the hazard potential resulting from the
    release of toxic materials; rather, it intends to suggest that for a
    retrospective event, such as events at Khamisiyah, the use of models that
    were not fully developed for deriving long-range environmental hazards, in
    conjunction with the uncertain source term data used, resulted in a flawed
    modeling outcome. As we mentioned before, DOD now asserts that it has made
    significant improvements in its models; however, we have not evaluated
    DOD's assertion, since this was beyond the scope of this study.

    3. 	An ensemble approach can be a useful tool in addressing issues of
    uncertainty. However, the process DOD used discounted at least two
    simulations using models that resulted in plume footprints that either
    were much larger or traveled in different directions or both. To properly
    account for uncertainty, and the untested ability of the several DOD
    models to estimate long-range environmental fallouts, other more mature
    models such as the MATHEW/ADPIC models from LLNL should have been included
    in the model. In the absence of their inclusion, evidence that the plumes
    did not travel in a divergent direction needs to be produced.

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    4. 	Again, our conclusion was not intended to suggest that modeling, or
    even ensemble modeling, is a flawed approach to predicting the hazard
    potential resulting from the release of toxic materials. Rather, it was
    intended to suggest that using models that were not fully developed for
    deriving environmental fallout estimates in conjunction with uncertain
    source term data resulted in a flawed modeling outcome and unsupported
    results. In addition, the selection of data and sites for modeling has a
    profound impact on model predictions. It is this area of the use of
    incomplete and improbable data and uncertainty in the selection criteria
    for sites and times to model that has resulted in flawed modeling
    outcomes.

    5. 	The objectives of this report were not to evaluate DOD's modeling
    capabilities in general but, rather, to (1) determine the validity of DOD
    and British Ministry of Defense (MOD) conclusions-based on CIA and DOD
    plume-modeling results- regarding U.S. and British troops' exposure to CW
    agents during the 1991 Gulf War; (2) determine the total costs for the
    CIA's and DOD's various plumemodeling efforts related to these exposures;
    and (3) determine DOD and VA conclusions from epidemiological studies,
    based on DOD's plume-modeling results, that there was no association
    between CW exposure at Khamisiyah and the troops' hospitalization and
    mortality rates. In other words, we examined how DOD's capabilities were
    applied to this specific case.

    6. This comment is dealt with in detail in addressing specific DOD
    comments below.

    7. 	Our observation regarding inaccurate, inappropriate, and incomplete
    source term data and assumptions would apply equally to simulations
    conducted throughout the period from 1996 to the present. Because flawed
    data were fed into those models, the fact remains that the modeling
    results are unsupported. As we mentioned before, DOD now asserts that it
    has made significant improvements in its models; however, we have not
    evaluated DOD's assertion, since it was beyond the scope of this study.

    8. 	The report refers to panels of experts who reviewed DOD reports and
    made comments and recommendations regarding the DOD modeling efforts. In
    at least one case, we have documented where an expert made a
    recommendation regarding the potential presence of meteorological
    phenomena not addressed in the DOD modeling studies.

    9. 	We reviewed all published studies as well as technical reports DOD and
    VA prepared. We agree with DOD that "scientifically peer-reviewed and
    published" is considered a high standard of validity when it implies
    anonymous review by scientists coordinated by the editor of a reputable
    scientific journal leading to publication of findings in that scientific
    journal. The peer review and 2000 publication to which DOD refers here had
    not gone through that process. The 2002 Kang and Bullman study has not
    been published in a peer-reviewed journal

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    and therefore should not have been included in a review of the scientific
    epidemiologic literature. This subject is discussed in further detail in
    our response to DOD's comments on the section "DOD's and VA's
    Epidemiological Conclusions on CW Exposure and Hospitalization and
    Mortality Rates Cannot Be Adequately Supported."

    10. As mentioned in response to comment 7 above, the inaccurate,
    inappropriate, and incomplete source term data and assumptions that we
    describe in the report would apply equally to simulations conducted
    throughout the period from 1996 to the present. The statement in appendix
    I reflects DOD's chronology of modeling events, not our assessment or
    conclusion.

    11. One of the central conclusions of our report is that DOD's plume
    modeling was flawed, and this conclusion applied to the 2000 plume
    modeling as well as to the 1997 plume modeling. As for the comment that
    "GAO never mentions several completed epidemiology studies that used the
    results of the 2000 plume modeling," these studies were not mentioned for
    varying reasons. Smith and others, showed that hospitalization rates for
    several ICD-9 diagnoses were higher in veterans categorized in the
    Khamisiyah 2000 plume than in those not in the plume, and the association
    for cardiac arrhythmias was statistically significant. However, that study
    suffered from the same deficiencies as the earlier study that we
    cited-namely, inappropriate use of hospitalization outcome measures rather
    than appropriate use of measures of Gulf War illness, which usually do not
    result in hospitalization, and use of plume modeling based on flawed data.
    The 2002 Kang and Bullman study has not been published in a peer-reviewed
    journal and therefore should not have been included in a review of the
    scientific epidemiologic literature. This subject is discussed in further
    detail in our response to DOD's comments on the section "DOD's and VA's
    Epidemiological Conclusions on CW Exposure and Hospitalization and
    Mortality Rates Cannot Be Adequately Supported."

    In response to the comment that "GAO's review of the literature is
    selective [and] incomplete," we do not agree with this characterization of
    the literature review. We reviewed all published literature. The review of
    the literature was focused on assessing the validity of DOD and VA
    conclusions from the epidemiological studies, based on DOD's
    plume-modeling results that there was no association with CW exposures at
    Khamisiyah and troops' hospitalization and mortality rates. We address
    specific reasons for excluding reports DOD identified in our response to
    DOD's comments in the section "DOD's and VA's Epidemiological Conclusions
    on CW Exposure and Hospitalization and Mortality Rates Cannot Be
    Adequately Supported."

    With respect to the comment that we ignored the Department of Defense
    Low-Level Chemical Warfare Agents (CWAs) Research Master Plan, June 2003,
    or the results of any of the research indicated in the plan, we repeat
    that the review of

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    the literature was focused on assessing the validity of DOD and VA
    conclusions from the epidemiological studies, based on DOD's
    plume-modeling results that there was no association with CW exposures at
    Khamisiyah and troops' hospitalization and mortality rates.

    With regard to the comment that "GAO does not explain what it thinks would
    be a better method to assess exposure," we believe that some of the
    methodologies we cite in this report provide valuable insight into the
    identification of both the effects of exposure and those who were likely
    to have been affected by exposure. The methodologies include the
    identification of biomarkers or genetic polymorphisms, animal model
    studies that attempt to recreate the suspected event and evaluate the
    appearance of a similar outcome, epidemiological studies in which the
    cohort classifications can be safely made (such as deployed, nondeployed,
    or deployed outside the period of potential exposure).

    Regarding the comment that we "appear to favor some studies of 1991 Gulf
    War veterans that are mentioned on pages 52 to 61 [now 50 to 55], which
    seems to imply that GAO thinks these studies used a superior method of
    exposure assessment, compared to the DOD modeling," we believe that in the
    absence of more reliable meteorological and source term data relating to
    the 1991 Gulf War, the DOD plume modeling must be considered inferior to
    other methodologies that avoid the selection bias likely to be introduced
    as a result of using the DOD Khamisiyah ensemble plume modeling, for the
    reasons cited in this report.

    Concerning the comment "some of the studies GAO mentioned did not evaluate
    possible chemical warfare exposure at all," we evaluated only studies that
    examined possible CW agent exposure, genetic polymorphisms believed to be
    associated with CW agent exposure, animal model studies associated with CW
    agent exposure, and studies that used the DOD ensemble plume models (1997,
    2000).

    12. The initiation of the bombing of Iraq's CW research, production, and
    storage sites began on January 17, 1991. The release of environmental
    hazards associated with the open-air destruction of these facilities would
    have commenced on that date rather than on the ground invasion that began
    on February 25, 1991. U.S .and British forces did not have to penetrate
    these sites to be at risk from the potential health consequences of the
    fallout of material released as a result of these bombings. In addressing
    fallout, we were referring to hazardous materials thrust into the air and
    potentially exposing troops to CW agents at subacute levels at significant
    distances downwind. "Located near" is a relative term intended only to
    reflect that the troops were close enough to be at risk for exposure. This
    is not only our observation; it was also a concern of the war planners
    before the onset of Operation Desert Storm, as reflected by requests for
    hazard assessments modeling the U.S. Air Force made to Lawrence Livermore
    National Laboratories.

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    13. We concur and the report has been clarified accordingly.

    14. We concur and the report has been clarified accordingly.

    15. We concur with this comment and have clarified the report accordingly.

    16. We concur with this comment and have clarified the report accordingly.

    17. Our statement addresses not how DOD classified the troops during the
    modeling process but, rather, how researchers later used these data to
    classify troops into exposed and not exposed study cohorts in conducting
    health-related studies.

    18. Our determination that conclusive classification criteria are
    unsupported does not mean or assume that the entire population was
    exposed. But the classification by researchers is not supported by
    reliable scientific, or any other, evidence since the determination of who
    was and who was not exposed is based on flawed and inaccurate data and the
    exclusion from the ensemble modeling estimates of modeling simulations
    that projected larger and directionally divergent potential exposure
    areas. Given the uncertainty associated with determining who was and who
    was not exposed and with determining whether or not the demolition of the
    Khamisiyah pit represents a single exposure event, researchers will have
    to assess, independent of the modeling performed and the ensemble
    projections, who was and who was not exposed.

    The observation that not all those who were exposed are ill applies
    equally, whether the DOD models and the ensemble estimates are viewed as
    accurate or flawed. This phenomenon is much more likely to be attributable
    to the genetic susceptibility of certain individuals to be physically
    affected by exposure at varying exposure levels.

    19. The recommendation is intended to apply only to the 1991 Gulf War, and
    we have amended the recommendation to clarify its intent.

    20. While it is not part of modeling methodology, it was part of the
    process DOD used in examining this issue. The report has been clarified.

    21. We concur with this comment and have clarified the report accordingly.

    22. DOD is correct in characterizing SCIPUFF as a component of HPAC and we
    have changed the language accordingly. DOD comments regarding NUSSE and
    ADPIC, however, are contradicted by the record. On September 4, 1997, the
    CIA and DOD issued a report entitled "Modeling the Chemical Warfare Agent
    Release at the Khamisiyah Pit (U)." In that report, the CIA identified
    transport and diffusion models used in this effort to include SCIPUFF,
    VLSTRACK, and NUSSE4. The MATHEW/ADPIC suite of models were, based on
    documentation supplied to us by

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                  Appendix VI: Comments from the Department of Defense

    officials at the National Atmospheric Release and Advisory Capability,
    Lawrence Livermore National Laboratory, used in simulations of the
    Khamisiyah pit performed at the request of IDA in late 1996 and early
    1997.

    23. The section DOD cites does not imply that DOD or the CIA suggested
    that there can be "definitive conclusions" from the modeling process.
    Rather, it states that "The models are neither sufficiently certain nor
    precise to draw definitive conclusions about the size or path (that is,
    the direction) of the plumes." It was the use of this information to
    define study cohorts in follow-on government funded health-related
    research that resulted in our comment.

    24. We concur with this comment and have clarified the report accordingly.
    However, the MATHEW/ADPIC models were used in the simulations of the
    Khamisiyah pit, performed at IDA's request in late 1996 and early 1997.

    25. DOD is correct that MM5 and COAMPS are commonly used mesocale
    meteorological models. However, when they were used with dispersion models
    (such as VLSTRACK), which were not fully developed for long-range
    environmental hazards and in conjunction with uncertain meteorological and
    source term data, meteorological models such as MM5 could not overcome the
    limitations of the dispersion models. The validation of VLSTRACK at 220 km
    still falls far short of the distances contemplated in this report.

    26. This statement is based on an internal DOD memorandum, dated December
    18, 1998, with the subject "Discounting the Results of the Omega Version
    3.5 for the Khamisiyah Reanalysis and Al Muthanna Analysis." The
    memorandum states that the Omega consistently underpredicts surface wind
    speeds by a factor of 2 to 3 from actual observation collected at the five
    world meteorological stations in the area.

    27. This statement is based on a 1999 IDA report evaluating the variance
    of VLSTRACK and HPAC predictions for the dispersion of chemical and
    biological warfare agents. The IDA report noted that for chemical
    releases, the HPAC and VLSTRACK predictions of areas of hazard differed
    substantially and that for biological releases they differed by factors of
    5 and 1,000.

    28. The statement DOD quotes is based on a 1998 memorandum from DOD's
    Deputy for Counterproliferation and Chemical and Biological Defense. This
    memo states: "VLSTRACK and HPAC generate hazard predictions that are
    significantly different from an operational perspective." Correspondence
    to GAO from the Deputy's Modeling and Simulation Advisor noted that "the
    1998 project found significant errors in the coding of one of the models
    such that for analyses conducted prior to that date, I would not consider
    that model reliable for use."

    29. We concur with this comment and have clarified the report accordingly.

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                  Appendix VI: Comments from the Department of Defense

    30. It is, in part, this observation that causes us to view as uncertain
    the plume data DOD subsequently presented. Even the most elegant and
    precise model will provide inaccurate results if it uses inaccurate data.

    31. We reported that "Assumptions about the purity of the CW agents sarin
    and cyclosarin established for Khamisiyah, Al Muthanna, Muhammadiyat, and
    Ukhaydir differed widely. In each case, agent purity was a key factor in
    the CIA and DOD methodology for determining the amount of agent released.
    For example, for modeling purposes, 10 tons of agents with a purity of 18
    percent would be represented as 1.8 tons of agent. The CIA relied on
    UNSCOM reporting on the amount of CW agents Iraq produced. But to
    establish these rates, UNSCOM relied primarily on Iraqi declarations and
    Iraqi production records, as well as assumptions about the extent of agent
    degradation." This section was included to demonstrate that varying rather
    than consistent methodologies of differing levels of credibility were used
    in deriving the estimated agent purity. It was also used to explain the
    methodology used by the CIA and DOD in determining the maximum amount of
    agent available for dispersion. The report was clarified to address DOD's
    comment.

    32. We were not suggesting that complete transfer occurred. Rather, we
    were providing other science-based evidence that is contrary to the
    earlier DOD observation that little or no transfer occurred. The
    overpressures generated by high explosives have to go somewhere. In a
    building, the structure would be destroyed. In a bunker, if the structure
    were not destroyed, this overpressure release would occur through the
    openings in the structure.

    33. The photographs DOD referred to show the view from the opening in the
    top of Bunker 2, as well as several aerial views. According to UNMOVIC,
    however, UNSCOM did not physically inspect this bunker for safety reasons
    relating to structural instability. This observation seems to be confirmed
    by the photos referred to in the report DOD cited.

    34. Given the images available, while the munitions may not have been
    targeted directly, they certainly seem to have been hit.

    35. We are aware of the design of the Dugway testing and its purpose to
    simulate the demolitions at the Khamisiyah pit. Contrary to the DOD's
    assertion, the use of Dugway testing data for evaporation and degradation
    at Muhammadiyat is inappropriate for either leakage or destruction by
    high-explosive bombs, neither of which were approximated by the conditions
    at Dugway or at Khamisiyah. For example, the type and quantity of
    explosives used in the Dugway testing and, therefore, the resulting
    effects were not comparable to the type and quantity of munitions that
    were actually used at Muhammadiyat. At Dugway Proving Ground, small
    explosive charges were placed on boxed rockets; at Muhammadiyat, the
    munitions were targeted with multiple high-explosive bombs.

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                  Appendix VI: Comments from the Department of Defense

    36. The CIA Report on Intelligence Related to Gulf War Illnesses, dated
    August 2, 1996, included modeling of Bunker 73 and identified the effort
    as being done by the CIA in parallel with DOD's Persian Gulf Investigative
    Team, to determine whether U.S. troops were exposed to chemical and
    biological warfare agents during the Gulf War. The CIA's effort did not
    seek to duplicate DOD's; however, CIA analysts drew on and examined DOD
    information to clarify intelligence, obtain leads, and ensure a thorough
    and comprehensive intelligence assessment. We have clarified the report to
    reflect that this was a CIA modeling effort.

    37. According to Iraqi declarations and UNSCOM, the stocks at Bunker 73
    were part of the same lot as that discovered at the Khamisiyah pit, and
    the munitions in the pit were estimated to have a purity of up to 50
    percent when demolitions occurred. Therefore, a 2.5 percent purity rate is
    not supported. We concur that the earlier modeling and source term were
    performed by the CIA; however, later, after the IDA panel judged the
    models used in the early modeling efforts to be inappropriate, no effort
    was made to reexamine the releases from this site.

    38. Our statement was taken out of context. The entire statement reads
    "DOD reported that the Al Muthanna research, production, and storage
    facility for CW agents was repeatedly attacked. Despite its repeated
    bombing, however, on only one occasion did the CIA and DOD express any
    concern about agent release. According to DOD analysis of the destruction
    of Bunker 2 at Al Muthanna on February 8, 1991 . . . ." This is to suggest
    not that the CIA and DOD are unconcerned about this issue but only that
    they were only sufficiently concerned to publish the results of their
    modeling in connection with this singular event at Al Muthanna, despite
    the repeated bombings of this principal Iraqi CW agent research,
    production, and storage facility.

    39. We do not agree with DOD. According to UNMOVIC, UNSCOM never inspected
    this bunker for safety reasons.

    40. We explained the methodology used by DOD and have clarified the report
    by deleting the comparison with Khamisiyah.

    41. This section refers to the detections identified in table 4, of the
    report, now on p.

    26. The comment that no confirmatory testing was conducted is not
    accurate. The Czech chemical detection unit reported the detections to
    U.S. command officials immediately, as is reflected in both the Czech and
    CENTCOM NBC logs, but the responding units were unable to confirm their
    findings when they arrived hours after the initial detections on January
    19, 1991, and were unable to confirm these reports. However, in addition
    to the field detections, the Czech chemical detection units conducted
    reagent based wet chemistry confirmation tests that supported the findings
    of the initial detections. The French never officially acknowledged the
    detections attributed to their units; however, the CENTCOM NBC logs again
    noted that the French reported detecting chemical nerve agents on January
    19,

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                  Appendix VI: Comments from the Department of Defense

    1991, and that the Czechs confirmed the French detections. In addition,
    according to an Agence France Presse report, on February 4, 1991, General
    Raymond Germanos, a spokesperson for the French Ministry of Defense, was
    attributed as having confirmed that chemical fallout, "probably
    neurotoxins" had been detected in small quantities, "a little bit
    everywhere," from allied air attacks of Iraqi CW facilities and the depots
    that stored them.

    42. Since this NOAA-11 AVHRR-1B imagery was being used to demonstrate
    meteorological activity between January 18 and January 23, 1991, and not
    at some specific time, the exact time each image was captured will not add
    to or detract from its evaluation.

    43. The coincidence between these and other events involving the
    destruction of Iraq's CW agent research, production, and storage
    infrastructure using aerial bombs and cruise missiles, and the reported
    airborne detections of CW agents by Czech, French, U.S., and British
    forces (see table 4) suggest that DOD and the CIA should have reassessed
    their positions regarding the potential for additional exposure events.

    44. We concur and the figure has been clarified accordingly.

    45. The discussion in this section of the report deals with temperature
    inversions. Unlike a capping inversion, which is almost a constant feature
    in the atmosphere, a temperature inversion is not. When a temperature
    inversion occurs, air pollutants can be trapped near the surface of the
    Earth.

    46. Figure 4 has been corrected to axis labels and time of day 0008Z.

    47. In the April 2002 Gulf War Illness Task Force Report, "Intelligence
    Update: Chemical Warfare Agent Issues during the Persian Gulf War," the
    CIA assessed that "the Czech detections were unlikely to be from a
    chemical agent." The Czech chemical detection units conducted wet
    chemistry confirmation tests supporting the initial detections. We have
    clarified the report to remove the reference to DOD in the relevant
    sentence.

    48. We agree that the initial modeling referred to was that performed by
    LLNL for IDA and not included in the DOD ensemble model. This modeling
    effort actually assumed fewer rockets destroyed than were later assessed
    to be present at Khamisiyah and that produced a plume path considerably
    larger and more divergent from those selected for use in the DOD ensemble.

    49. The use of the power-law formula was intended to illustrate the
    unreasonable heights assumed during the DOD modeling efforts. Clearly not
    all the agent would be released simultaneously into the atmosphere and the
    agent released would be distributed throughout the plume geometry, but the
    power-law formula also

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                  Appendix VI: Comments from the Department of Defense

    projects the plume height at time = 2 minutes. After that time, the plume
    continues to grow in height. In some cases, at time = 5 minutes the plume
    heights nearly double. Further, the distribution used in the Khamisiyah
    pit is based on field and laboratory testing conducted at Dugway Proving
    Ground that inadequately simulated the conditions at the pit and did not
    simulate conditions at the other sites modeled at all. We concur that the
    Khamisiyah pit demolition, which occurred around 4:15 pm local time, when
    the atmospheric boundary layer was convective and well mixed, would have
    been insensitive to the argument of nocturnal low-level jet. The other
    sites, however, were bombed during the nighttime, and therefore this
    argument remains valid. The power-law formula demonstrates the
    relationship between the amount of explosives detonated and the resultant
    plume height. Whether this occurs by demolition or aerial bombing is
    irrelevant. The issue of top boundary versus centroid of the plume is
    addressed in our report (see figure 8). Regarding buoyant puff at
    Khamisiyah, DOD based its comment on Dugway field testing, which did not
    realistically simulate actual conditions at the Khamisiyah site.

    50. Videos of the demolition operations at Khamisiyah have been widely
    released. While we concur that videos do not show data, they can certainly
    demonstrate that DOD data assumptions, such as plume height estimates, are
    inaccurate, because the plume height was higher than DOD assumptions.

    51. Figure 6 shows the layers in which these activities occur. We have
    changed the report to clarify this reference.

    52. This statement should read "Empirical studies and observed events tend
    to refute the assumptions with which the CIA and DOD discounted the
    alternative assumption that the plume was transported by low-level jets."
    The empirical studies are those involving the likely plume heights reached
    in high-explosive explosions. The observed events are the reported
    detections of CW agents associated with temperature inversion activity and
    atmospheric turbulence. We changed the report accordingly.

    53. We did not make this assumption; rather, it is a possibility we were
    obliged to consider when evaluating the potential for the long-range
    transport of CW agents. It is precisely the absence of on-site
    measurements leading to this additional element of uncertainty for a
    phenomenon that is far from rare that has resulted in our questioning
    DOD's and CIA's discounting this phenomenon, despite having been cautioned
    to consider the possibility by a DOD expert consultant.

    54. Nothing in this section of the report suggests that either long-range
    advection (transport of pollution) or turbulence events occurs independent
    of dispersion or dilution. In fact, exposures occurring at these distances
    would almost by necessity be at low or subacute levels. The report also
    does not suggest that the low-level jets function independent of
    turbulence. But aircraft and artillery would

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                  Appendix VI: Comments from the Department of Defense

    produce a directional shift in turbulence, possibly resulting in mixing to
    the surface. The characterization of the MATHEW wind field model as one we
    favored is not accurate. The MATHEW/ADPIC suite simulations are simply
    demonstrative of the uncertainty associated with the modeling process.

    55. We understand the financial and practical limitations in conducting
    this sort of testing. Still, differences in experimental conditions can
    result in profound differences in outcome. For example, there may have
    been more agent dispersed immediately, leaving less to evaporate over time
    had the simulations been conducted under different conditions.

    56. We agree with this comment. Predictive modeling is a crucial asset and
    should be so considered. Retrospective modeling, however, in the absence
    of robust data is far more easily criticized as "deficient," not
    necessarily because of deficiencies in the models or the approach, but
    because of the lack of validated input data and a selection process that
    is subject to limited available data, an inexact intelligence assessment
    process, and the potential for individual bias.

    57. We do not agree with DOD's characterization. Despite not having
    modeled the same quantities, LLNL modeled a variety of release scenarios
    and used the meteorological data available for the region. This modeling
    effort actually assumed a similar number of rockets destroyed as were
    later assessed to have been destroyed at Khamisiyah by the CIA in 2002,
    yet it produced a plume path considerably larger and quite divergent from
    the models selected for use in the DOD ensemble. We do not understand why
    IDA characterized the model as less capable. The LLNL models had an
    established history of modeling the release of hazardous materials,
    including the 1991 Kuwaiti oil fires.

    In February 1991, during the last few days of the Gulf War, the Iraqis
    ignited about 605 oil wells, causing an unprecedented environmental
    disaster in the region. During spring and summer 1991, two working groups,
    one sponsored by the World Meteorological Organization in conjunction with
    the World Health Organization and the other consisting of the U.S.
    government's scientific community, conducted airborne sampling programs to
    evaluate the local and global consequences of these fires. The Atmospheric
    Release Advisory Capability (ARAC), incorporating the MATHEW/ADPIC
    modeling suite, provided daily forecasts of the location and density of
    the smoke plumes in support of these aircraft missions, and concurrently
    to all the countries affected.

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                  Appendix VI: Comments from the Department of Defense

    The modeling was performed in the same region and during the same general
    time

    as the Khamisiyah event and the 1986 nuclear reactor accident at
    Chernobyl.1 In

    conjunction with the Chernobyl event, LLNL's long-range particle-in-cell
    model

    accurately simulated the spread of the radioactive cloud over the entire
    northern

    hemisphere, as verified later by radiological measurements. The NARAC

    emergency response central modeling system LLNL currently uses consists of
    a

    coupled suite of meteorological and dispersion models. The data
    assimilation

    model ADAPT constructs fields of such variables as the mean winds,
    pressure,

    precipitation, temperature, and turbulence, using a variety of
    interpolation

    methods and atmospheric parameterizations. Nondivergent wind fields are

    produced by an adjustment procedure based on the variational principle and
    a

    finite-element discretization. The dispersion model LODI solves the 3D
    advection

    diffusion equation using a Lagrangian stochastic; LODI includes methods
    for

    simulating the processes of mean wind advection, turbulent diffusion,
    radioactive

    decay and production, bioagent degradation, first-order chemical
    reactions, wet

    deposition, gravitational settling, dry deposition, and buoyant/momentum
    plume

    rise. The models are coupled to NARAC databases providing topography,

    geographical data, chemical-biological-nuclear agent properties and health
    risk

    levels, real-time meteorological observational data, and global and
    mesoscale

    forecast model predictions. The NARAC modeling system also includes an in

    house version of the Naval Research Laboratory's mesoscale weather
    forecast

    model COAMPS. This is a mesoscale meteorological model that LLNL has

    incorporated into its modeling suite.

    58. Regarding the comment, "the source term is different," LLNL modeled a
    variety of release scenarios and used the meteorological data available
    for the region. This modeling effort actually assumed a similar number of
    rockets destroyed as were later assessed to have been destroyed at
    Khamisiyah by DOD in 2002, yet it produced a plume path considerably
    larger and quite divergent from the models selected for use in the DOD
    ensemble. According to DOD's technical report, "Modeling and Risk
    Characterization of U.S. Demolition Operations at the Khamisiyah Pit"
    (April 16, 2002), released by William Winkenwerder, Jr., Assistant
    Secretary of Defense (Health Affairs) and Special Assistant to the Under
    Secretary of Defense (Personnel and Readiness) for Gulf War Illnesses,
    Medical Readiness, and Military Deployments, the input source parameters
    used in the 1997 Khamisiyah pit modeling included a best estimate of 500
    rockets damaged in

    1F. W. Whicker and others, "PATHWAY: A Dynamic Food-Chain Model to Predict
    Radionuclide Ingestion after Fallout Deposition," Health Physics 52
    (1987): 717-37; L. R. Anspaugh and others, "The Global Impact of the
    Chernobyl Reactor Accident," Science 242 (1988): 1513-19; T. Straume and
    others, "The Feasibility of Using I129 to Reconstruct I131 Deposition from
    the Chernobyl Reactor Accident," Health Physics 71:5 (1996): 733-40; K. T.
    Bogen and others, Uncertainty and Variability in Updated Estimates of
    Potential Dose and Risk at a U.S. Nuclear Test Site Bikini Atoll,
    UCRL-JC-122616 (Livermore, Calif.: Lawrence Livermore National Laboratory,
    1995).

    Page 103 GAO-04-159 Gulf War Illnesses

                  Appendix VI: Comments from the Department of Defense

    demolition, based on UNSCOM reporting and intelligence information.
    According to the report, this number could be as high as 650 or as low as
    170, based on number of rockets minus rockets found by UNSCOM that were
    undamaged. The same report estimated that the total number of rockets in
    the pit was 1,250. Again, according to the report, this number could be as
    high as 1,400 or as low as 1,100, based on size of crates and stacks of
    rockets.

    Regarding the comment "area-defining thresholds are different," we concur.
    However, the legend in figure 10 acknowledges this difference. Regarding
    the comment "dosage accumulation times are different," we concur. Again,
    however, this issue is addressed in the footnote defining these factors.
    Regarding the comment "meteorological fields are different," again, we
    concur with this observation. However, this comment is self-evident in
    that the plume is moving in a different direction. It is important to note
    that the corrections above do not have any effect on our conclusions. The
    use of the composite image is intended to illustrate that the use of
    different models, based on different underlying principles and
    assumptions, can result in different outcomes. In that regard, it is not
    misleading.

    The fact that Iraq is a data-sparse region only serves to strengthen our
    observation that the uncertainty associated with attempting to model the
    fallout from the Khamisiyah pit, and to an equal or greater degree the
    other sites modeled, is too great to provide meaningful results. If an
    ensemble approach is to be attempted, then a range of methodologies needs
    to be incorporated.

    59. That our language "could be explained" suggests that it is only one
    possible reason. When we interviewed researchers at LLNL, they noted that
    this diffluence may account for the different outcomes.

    60. Figure 12 not only illustrates intermodel bias; it also illustrates
    model, and potential ensemble, bias. In the case illustrated, an ensemble
    of the three models would still not incorporate the area containing the
    actual hazard. We concur that ensemble modeling is essential in minimizing
    uncertainty and providing hazard warning. But as illustrated by figure 12,
    even in using an ensemble approach, significant uncertainty remains.

    61. Our report has been clarified to reflect the use of consistent source
    term for SCIPUFF and VLSTRACK in the 2000 modeling. This reconciliation in
    source term does not, however, change any of our other observations or
    recommendations regarding the uncertainty associated with the source term,
    including the observation that, even with harmonized source, model
    projections still differ.

    62. We do not agree that this is a misleading statement. While each of
    DOD's modeled plumes was based on data, the composite or ensemble plume
    was based on a

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                  Appendix VI: Comments from the Department of Defense

    simple graphic overlay of the projection of the three component plumes.
    The relationship between these plumes, therefore, was not based on data.

    63. One of the central conclusions of our report is that DOD's plume
    modeling was flawed, and this conclusion applied to the 2000 plume
    modeling as well as to the 1997 plume modeling, because both suffered from
    the same weaknesses. That is, the models were not fully developed for
    long-range environmental hazards, and source term and input data were
    incomplete. Regarding the comment that "Several relevant studies have been
    published . . . that GAO did not mention," we have now incorporated these
    studies in our report.

    64. As we explained in our report, the PON group of enzymes is a
    potentially important predisposing factor in Gulf War illnesses because
    one of its major functions in normal body physiology is to protect the
    nervous system from organophosphate chemical toxins, such as pesticides
    and nerve agents. This finding was remarkable because the only function of
    Q type of the PON enzyme group is to protect the nervous system from nerve
    agents sarin, soman, tabun, and VX. The R-type isoenzyme has as its main
    function protection from organophosphate pesticides, such as diazinon,
    malathion, and parathion. Thus, an association between Gulf War illnesses
    and blood levels of only the Q-type isoenzyme of PON points specifically
    to nerve agent exposure. Therefore, they were being cited to illustrate
    studies that have examined paraoxonase deficiencies in veterans reporting
    Gulf War Syndrome.

    DOD's second paragraph is inaccurate. We did review the three studies
    cited in DOD, footnote 14. First, we rejected the Greenberg and others
    reference (second citation in DOD footnote 14). It is a letter to the
    editor merely commenting on possible errors in the recall of vaccine
    receipt in British Gulf War veterans; it did not deal with self-reports of
    CW agents and was not peer reviewed.

    The two other studies DOD cited, McCauley and others (the first citation
    in DOD's footnote 14) and Wessely and others (the third citation in DOD's
    footnote 14) both reported studies that measured the level of agreement on
    self-reported endorsement of various wartime environmental exposures in
    ill and well Gulf War veteran populations. These studies do not
    demonstrate recall bias. In fact, they contradict that claim. DOD has
    overlooked that recall bias results from nondifferential misclassification
    of exposure measurements in the case and control groups. Simply finding
    that some veterans misreported their exposures does not establish recall
    bias; other criteria are required to establish that. Both studies showed
    moderate to good levels of test-retest agreement (kappa >0.4) on
    self-reports of CW agent exposure, but, more importantly, the level of
    test-retest agreement (kappa statistic) did not differ between the ill and
    well groups. This means that whatever errors in recall occurred were
    nondifferential (occurred at the same rate in both groups), and therefore
    they did not bias the estimates of the

    Page 105 GAO-04-159 Gulf War Illnesses

                  Appendix VI: Comments from the Department of Defense

    relative risks for CW agent exposure. This means also that the errors in
    recall did not result in recall bias.

    65. In suggesting that "Most" of the animal studies "cannot be directly
    extrapolated to the possible health effects of low-level sarin exposure in
    1991 Gulf War veterans," DOD has missed the important developments in
    recent studies cited in our report that can be directly extrapolated to
    the health effects of low-level sarin exposure in the 1991 Gulf War. The
    best examples are the DOD-funded experiments by Henderson and others from
    the Lovelace Respiratory Research Institute and from the U.S. Army Medical
    Institute of Chemical Defense (Toxicol Appl Toxicol 184 (2002): 67-76).
    This study modeled the low-level inhalation exposure in rodents to sarin,
    with and without heat stress. No immediate health effects were measured by
    clinical indicators and brain pathological examination. However, 30 days
    after cessation of exposure, the rodents were found to have developed
    physical evidence of brain cell damage, demonstrated using sophisticated
    microscopic, neurochemical brain examination techniques. Once structural
    changes are found, the capability of sarin to cause chronic brain illness
    is established, and following the animals in the longer term is
    unnecessary. Other studies we cited add depth to the significant findings
    of Henderson and others and establish a body of evidence demonstrating the
    potential of subacute sarin exposures to cause brain cell damage and
    related chronic symptoms.

    66. DOD's response fails to distinguish between veterans having only
    symptoms relating to different organ systems and veterans having classic
    diseases of those organ systems to which physicians assign ICD-9 codes and
    for which they often hospitalize patients. The public health problem of
    1991 Gulf War veterans is characterized by a collection of symptoms of
    various organ systems in which physicians typically do not recognize
    classic, diagnosable diseases for which ICD9 codes exist. And since
    veterans with this problem are generally not critically ill enough to
    require hospitalization, their physicians do not hospitalize them more
    commonly than they do veterans without the condition. This is why DOD and
    VA studies with hospitalization as the outcome have not been productive.

    The Gulf War illness manifested by serious symptoms but no physical signs
    is the example of chronic illness in 1991 Gulf War veterans that would not
    lead to hospitalization. Recent studies by several investigators at
    different institutions have shown that this set of conditions stems from
    physical damage to brain cells in deep parts of the brain.

    By stressing that DOD "hospitalization data are very complete for
    active-duty personnel," DOD overlooks the significant selection bias that
    results from studies that rely on DOD hospitalization data alone as an
    outcome measure. Since most of the more severely ill Gulf War veterans
    left the military soon after the 1991 Gulf War, they were no longer
    eligible for hospitalization in DOD hospitals and, thus, their further
    hospitalizations were no longer counted. This "attrition" of the most

    Page 106 GAO-04-159 Gulf War Illnesses

                  Appendix VI: Comments from the Department of Defense

    ill veterans creates a strong selection bias in these studies toward
    falsely negative findings.

    Gray and others (DOD's footnote 16) fails to address the observation that
    Gulf War illness does not satisfy the diagnostic criteria for ICD-9 codes
    for the illness categories Gray and others studied-for example, infectious
    diseases, neoplasms, endocrine diseases, and blood diseases. Gray's
    finding that these classic diagnoses, defined by ICD-9 codes, were no more
    common in those who left the military soon after the war does not address
    the issue of selection bias from using DOD hospital data. To the contrary,
    other data Gray and others provided in their 1996 paper, reviewed by Haley
    (Am J Epidemiol 148 (1998): 325-23), demonstrated conclusively that
    military personnel discharged soon after the war did have largely
    different reasons for being discharged from the service, which points to a
    selection bias.

    The references to the studies involving the California Office of Statewide
    Health Planning and Development and VA are not relevant in assessing the
    health effects of CW agent exposure, because these studies did not relate
    illness to CW agent exposure measures.

    67. We did review all the studies cited but found them unsuitable for
    consideration for the following reasons. Smith and others (DOD's footnote
    17) used inappropriate outcome measures (ICD-9 diagnoses made in
    hospitalized patients) and unsupported measures of CW agent exposure-that
    is, the 2000 Khamisiyah plume model addressed in the report. Consequently,
    no useful conclusions can be derived from it. Kang and Bullman (DOD's
    footnote 18) is an internal VA technical report that has not been peer
    reviewed or published in a scientific journal and therefore is not
    appropriate for inclusion in a review of the scientific epidemiologic
    literature. McCauley and others (the first citation in DOD's footnote

    19) found that 1991 Gulf War veterans who witnessed the Khamisiyah
    demolition (a more valid measure of Khamisiyah exposure than the flawed
    plume models) had more chronic symptoms on average than those who did not
    witness it. This study suggests a causal role of Khamisiyah-associated
    sarin exposure in chronic Gulf War illness. We did not include the paper
    by Shapiro, Lasarev, and McCauley (second citation in DOD's footnote 19)
    because an anomalous problem with its factor analysis method appeared to
    disqualify its findings on a methodological basis. The investigators
    performed factor analysis of symptoms in a random sample of 1991 Gulf War
    veterans and found that those who actually witnessed the Khamisiyah
    demolition were significantly more likely to have their syndrome factor 2
    ("dysesthesia syndrome"). While this appears to support a causal role of
    Khamisiyah-associated sarin exposure in chronic Gulf War illness, the
    authors also reported that their factor analysis method was unreliable
    when applied to randomly generated variables. If this study were included,
    however, it would suggest a causal link with CW agent exposure. As for the
    two studies by Smith and

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                  Appendix VI: Comments from the Department of Defense

    others (DOD's footnote 20), we did not include these because both used
    participation in the DOD and VA registries as a proxy case-definition for
    Gulf War illness. Since military personnel and veterans were free to
    participate in the registry, regardless of whether or not they were ill
    or, if ill, the nature of their illness, registry participation is an
    entirely nonspecific measure and not suitable for scientific research on
    the problem. The two studies showed that registry participation and
    hospitalization were more common in veterans who were present at the
    Khamisiyah risk area than those who were not. Although the findings would
    support a causal link of CW agent exposure and illness, their methods do
    merit inclusion in a scientific literature review.

    68. We believe that the images in figure 17 are adequate to demonstrate
    the modeled diffluence in wind field data. While we cannot improve the
    quality of the figure, we have added an arrow to show the diffluence.

    Page 108 GAO-04-159 Gulf War Illnesses

    Appendix VII: Comments from the Central Intelligence Agency

    (460530) Page 109 GAO-04-159 Gulf War Illnesses

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